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<?xml version="1.0" encoding="utf-8"?>
<search>
<entry>
<title>Flutter 对齐与相对定位</title>
<link href="/2022/05/29/fe66a5355c28.html"/>
<url>/2022/05/29/fe66a5355c28.html</url>
<content type="html"><![CDATA[<h1 id="对齐与相对定位（Align）"><a href="#对齐与相对定位（Align）" class="headerlink" title="对齐与相对定位（Align）"></a>对齐与相对定位（Align）</h1><p>定义</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">Align({</span><br><span class="line"> <span class="keyword">this</span>.alignment = Alignment.center,</span><br><span class="line"> <span class="keyword">this</span>.widthFactor,</span><br><span class="line"> <span class="keyword">this</span>.heightFactor,</span><br><span class="line"> Widget child,</span><br><span class="line">})</span><br></pre></td></tr></table></figure><ul><li>alignment : 需要一个AlignmentGeometry类型的值，表示子组件在父组件中的起始位置。AlignmentGeometry 是一个抽象类，它有两个常用的子类：Alignment和 FractionalOffset，我们将在下面的示例中详细介绍。</li><li>widthFactor和heightFactor是用于确定Align 组件本身宽高的属性；<ul><li>它们是两个缩放因子，会分别乘以子元素的宽、高，最终的结果就是Align 组件的宽高。</li><li>如果值为null，则组件的宽高将会占用尽可能多的空间。</li></ul></li></ul><span id="more"></span><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">Container(</span><br><span class="line"> height: <span class="number">120.0</span>, <span class="comment">// 高度父组件决定</span></span><br><span class="line"> <span class="comment">// width: 120.0, // 宽度使用align确定， 优先级大于子组件</span></span><br><span class="line"> color: Colors.blue.shade50,</span><br><span class="line"> child: Align(</span><br><span class="line"> widthFactor: <span class="number">3</span>, <span class="comment">// 宽度为自身的3倍， </span></span><br><span class="line"> <span class="comment">// 当align和父组件都设置了的话，父组件的生效</span></span><br><span class="line"> alignment: Alignment.topRight, <span class="comment">// 对齐位置是右上角, 即子组件和父组件的右上角对齐</span></span><br><span class="line"> child: FlutterLogo(</span><br><span class="line"> size: <span class="number">60</span>,</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><img src="/2022/05/29/fe66a5355c28/16538377129777.jpg" class=""><h3 id="Alignment"><a href="#Alignment" class="headerlink" title="Alignment"></a>Alignment</h3><p>定义：<code>Alignment(this.x, this.y)</code><br>Alignment继承自AlignmentGeometry，表示矩形内的一个点，他有两个属性x、y，分别表示在水平和垂直方向的偏移<br>Alignment Widget会以矩形的中心点作为坐标原点，即Alignment(0.0, 0.0) 。x、y的值从-1到1分别代表矩形左边到右边的距离和顶部到底边的距离，因此2个水平（或垂直）单位则等于矩形的宽（或高）； 如Alignment(-1.0, -1.0) 代表矩形的左侧顶点</p><p>具体偏移为<br>offset(x, y) = (Alignment.x * childWidth / 2 + childWidth / 2, Alignment.y * childHeight / 2 + childHeight / 2)</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">Container(</span><br><span class="line"> height: <span class="number">120.0</span>, <span class="comment">// 高度父组件决定</span></span><br><span class="line"> <span class="comment">// width: 120.0, // 宽度使用align确定， 优先级大于子组件</span></span><br><span class="line"> color: Colors.blue.shade50,</span><br><span class="line"> child: Align(</span><br><span class="line"> widthFactor: <span class="number">3</span>, <span class="comment">// 宽度为自身的3倍， </span></span><br><span class="line"> <span class="comment">// 当align和父组件都设置了的话，父组件的生效</span></span><br><span class="line"> alignment: Alignment(<span class="number">2</span>, <span class="number">0</span>), <span class="comment">// 对齐位置为</span></span><br><span class="line"> child: FlutterLogo(</span><br><span class="line"> size: <span class="number">60</span>,</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><img src="/2022/05/29/fe66a5355c28/16538380684489.jpg" class=""><h3 id="FractionalOffset"><a href="#FractionalOffset" class="headerlink" title="FractionalOffset"></a>FractionalOffset</h3><p>FractionalOffset 继承自 Alignment，它和 Alignment唯一的区别就是坐标原点不同！FractionalOffset 的坐标原点为矩形的左侧顶点，这和布局系统的一致，所以理解起来会比较容易。<br>偏移指的是x y的偏移;</p><p>转换公式为：<br>实际偏移 = (FractionalOffset.x * childWidth, FractionalOffset.y * childHeight)</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">Align(</span><br><span class="line"> alignment: FractionalOffset(<span class="number">0.5</span>, <span class="number">1</span>),</span><br><span class="line"> child: FlutterLogo(</span><br><span class="line"> size: <span class="number">60</span>,</span><br><span class="line">),</span><br></pre></td></tr></table></figure><img src="/2022/05/29/fe66a5355c28/16538386017539.jpg" class=""><p>可以看到，Align和Stack/Positioned都可以用于指定子元素相对于父元素的偏移，但它们还是有两个主要区别：</p><p>定位参考系统不同；Stack/Positioned定位的的参考系可以是父容器矩形的四个顶点；而Align则需要先通过alignment 参数来确定坐标原点，不同的alignment会对应不同原点，最终的偏移是需要通过alignment的转换公式来计算出。<br>Stack可以有多个子元素，并且子元素可以堆叠，而Align只能有一个子元素，不存在堆叠。</p><h3 id="Center"><a href="#Center" class="headerlink" title="Center"></a>Center</h3><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">Center({</span><br><span class="line"> <span class="built_in">double?</span> widthFactor, </span><br><span class="line"> <span class="built_in">double?</span> heightFactor, </span><br><span class="line"> Widget? child </span><br><span class="line">})</span><br></pre></td></tr></table></figure><p>可以看到Center继承自Align，它比Align只少了一个alignment 参数；由于Align的构造函数中alignment 值为Alignment.center，所以，我们可以认为Center组件其实是对齐方式确定（Alignment.center）了的Align。</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line">DecoratedBox(</span><br><span class="line"> decoration: BoxDecoration(color: Colors.red),</span><br><span class="line"> child: Center(</span><br><span class="line"> child: Text(<span class="string">"xxx"</span>),</span><br><span class="line"> ),</span><br><span class="line">),</span><br><span class="line">DecoratedBox(</span><br><span class="line"> decoration: BoxDecoration(color: Colors.red),</span><br><span class="line"> child: Center(</span><br><span class="line"> widthFactor: <span class="number">1</span>,</span><br><span class="line"> heightFactor: <span class="number">1</span>,</span><br><span class="line"> child: Text(<span class="string">"xxx"</span>),</span><br><span class="line"> ),</span><br><span class="line">)</span><br></pre></td></tr></table></figure><img src="/2022/05/29/fe66a5355c28/16538388400806.jpg" class=""><p>两种偏移类Alignment 和FractionalOffset，区别及各自的坐标转化公式</p><p>在需要制定一些精确的偏移时应优先使用FractionalOffset，因为它的坐标原点和布局系统相同，能更容易算出实际偏移。</p>]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>Flutter 层叠布局</title>
<link href="/2022/05/28/68dbbde40c84.html"/>
<url>/2022/05/28/68dbbde40c84.html</url>
<content type="html"><![CDATA[<h1 id="层叠布局"><a href="#层叠布局" class="headerlink" title="层叠布局"></a>层叠布局</h1><p>层叠布局和 Web 中的绝对定位布局是相似的，子组件可以根据距父容器四个角的位置来确定自身的位置。层叠布局允许子组件按照代码中声明的顺序堆叠起来。<br>Flutter中使用Stack和Positioned这两个组件来配合实现绝对定位。<br>Stack允许子组件堆叠，而Positioned用于根据Stack的四个角来确定子组件的位置。</p><table><thead><tr><th align="center">Flutter</th><th align="center">SwiftUI</th></tr></thead><tbody><tr><td align="center">Row</td><td align="center">HStack</td></tr><tr><td align="center">Column</td><td align="center">VStack</td></tr><tr><td align="center">Stack</td><td align="center">ZStack</td></tr></tbody></table><span id="more"></span><h3 id="Stack"><a href="#Stack" class="headerlink" title="Stack"></a>Stack</h3><p>定义</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">Stack({</span><br><span class="line"> <span class="keyword">this</span>.alignment = AlignmentDirectional.topStart,</span><br><span class="line"> <span class="keyword">this</span>.textDirection,</span><br><span class="line"> <span class="keyword">this</span>.fit = StackFit.loose,</span><br><span class="line"> <span class="keyword">this</span>.clipBehavior = Clip.hardEdge,</span><br><span class="line"> <span class="built_in">List</span><Widget> children = <span class="keyword">const</span> <Widget>[],</span><br><span class="line">})</span><br></pre></td></tr></table></figure><ul><li>alignment：此参数决定如何去对齐没有定位（没有使用Positioned）或部分定位的子组件。所谓部分定位，在这里特指没有在某一个轴上定位：left、right为横轴，top、bottom为纵轴，只要包含某个轴上的一个定位属性就算在该轴上有定位。</li><li>textDirection：和Row、Wrap的textDirection功能一样，都用于确定alignment对齐的参考系，即：textDirection的值为.ltr，则alignment的start代表左，end代表右，即从左往右的顺序；textDirection的值为.rtl，则alignment的start代表右，end代表左，即从右往左的顺序。</li><li>fit：此参数用于确定没有定位的子组件如何去适应Stack的大小。StackFit.loose表示使用子组件的大小，StackFit.expand表示扩伸到Stack的大小。</li><li>clipBehavior：此属性决定对超出Stack显示空间的部分如何剪裁，Clip枚举类中定义了剪裁的方式，Clip.hardEdge 表示直接剪裁，不应用抗锯齿</li></ul><h3 id="Positioned"><a href="#Positioned" class="headerlink" title="Positioned"></a>Positioned</h3><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">Positioned({</span><br><span class="line"> <span class="keyword">this</span>.left, </span><br><span class="line"> <span class="keyword">this</span>.top,</span><br><span class="line"> <span class="keyword">this</span>.right,</span><br><span class="line"> <span class="keyword">this</span>.bottom,</span><br><span class="line"> <span class="keyword">this</span>.width,</span><br><span class="line"> <span class="keyword">this</span>.height,</span><br><span class="line"> <span class="keyword">required</span> Widget child,</span><br><span class="line">})</span><br></pre></td></tr></table></figure><ul><li>left、top 、right、 bottom分别代表离Stack左、上、右、底四边的距离。 </li><li>width和height用于指定需要定位元素的宽度和高度。<br>注意，Positioned的width、height 和其它地方的意义稍微有点区别，此处用于配合left、top 、right、 bottom来定位组件，举个例子，在水平方向时，你只能指定left、right、width三个属性中的两个，如指定left和width后，right会自动算出(left+width)，如果同时指定三个属性则会报错，垂直方向同理。</li></ul>]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>iOS Lock</title>
<link href="/2022/05/27/ab7dd047758f.html"/>
<url>/2022/05/27/ab7dd047758f.html</url>
<content type="html"><![CDATA[<h1 id="锁-🔒"><a href="#锁-🔒" class="headerlink" title="锁 🔒"></a>锁 🔒</h1><p>锁用于解决多线程间资源共享的安全问题</p><p>分类：</p><ul><li>自旋锁(Spinlock): 即忙等，类似 do-while，会一直占着CPU、内存等即忙碌状态</li><li>互斥锁(Mutex): 闲等，即锁的线程处于休眠状态<ul><li>非递归锁(non-recursive mutex)或称不可重入互斥锁(non-reentrant mutex): 同一时刻只能被一条线程所拥有</li><li>可递归锁(recursive mutex)或称可重入互斥锁(reentrant mutex): 同一时刻能被多条线程所拥有</li></ul></li><li>读写锁: 多读单写、读和写要互斥，有空再补<span id="more"></span></li></ul><h3 id="iOS中常见方案："><a href="#iOS中常见方案：" class="headerlink" title="iOS中常见方案："></a>iOS中常见方案：</h3><h4 id="OSSpinLock-自旋锁"><a href="#OSSpinLock-自旋锁" class="headerlink" title="OSSpinLock: 自旋锁"></a>OSSpinLock: 自旋锁</h4><p> 自iOS10移除，被os_unfair_lock替代，因为优先级反转(Priority inversion)问题，优先级高的线程会被系统持续优先调度，所以优先级低的线程一直在等待，无法执行任务<br> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">OSSpinLock lock = OS_SPINLOCK_INIT; <span class="comment">// 初始化</span></span><br><span class="line">OSSpinLockLock(&lock); <span class="comment">// 加锁</span></span><br><span class="line">OSSpinLockUnlock(&lock); <span class="comment">// 解锁</span></span><br><span class="line">OSSpinLockTry(&lock); <span class="comment">// 尝试上锁，false即失败，锁被其他线程持有</span></span><br></pre></td></tr></table></figure></p><h4 id="os-unfair-lock-互斥锁"><a href="#os-unfair-lock-互斥锁" class="headerlink" title="os_unfair_lock: 互斥锁"></a>os_unfair_lock: 互斥锁</h4><p> iOS10开始支持，用以替代不安全的OSSpinLock；<br> 等待锁的线程会处于休眠状态，<br> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">os_unfair_lock unfairLock = OS_UNFAIR_LOCK_INIT; <span class="comment">// 初始化</span></span><br><span class="line">os_unfair_lock_lock(&unfairLock); <span class="comment">// 加锁</span></span><br><span class="line">os_unfair_lock_unlock(&unfairLock); <span class="comment">// 解锁</span></span><br><span class="line">os_unfair_lock_trylock(&unfairLock); <span class="comment">// 尝试上锁</span></span><br></pre></td></tr></table></figure></p><h4 id="pthread-mutex-互斥锁"><a href="#pthread-mutex-互斥锁" class="headerlink" title="pthread_mutex: 互斥锁"></a>pthread_mutex: 互斥锁</h4><p> 线程在等待锁时会处于休眠状态<br> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//非递归</span></span><br><span class="line">pthread_mutex_t lock0;</span><br><span class="line">pthread_mutex_init(&lock0, <span class="literal">NULL</span>); <span class="comment">// 初始化</span></span><br><span class="line">pthread_mutex_lock(&lock0); <span class="comment">// 加锁</span></span><br><span class="line"><span class="comment">// ...</span></span><br><span class="line">pthread_mutex_unlock(&lock0); <span class="comment">// 解锁</span></span><br><span class="line">pthread_mutex_destroy(&lock0); <span class="comment">// 释放</span></span><br><span class="line"></span><br><span class="line"><span class="comment">//递归</span></span><br><span class="line">pthread_mutex_t lock1;</span><br><span class="line">pthread_mutexattr_t attr; <span class="comment">// 用于设置锁的类型</span></span><br><span class="line">pthread_mutexattr_init(&attr);</span><br><span class="line">pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); <span class="comment">// 递归</span></span><br><span class="line">pthread_mutex_init(&lock1, &attr); <span class="comment">// 初始化</span></span><br><span class="line">pthread_mutexattr_destroy(&attr); <span class="comment">// 释放</span></span><br><span class="line">pthread_mutex_lock(&lock1); <span class="comment">// 加锁</span></span><br><span class="line"><span class="comment">// ...</span></span><br><span class="line">pthread_mutex_unlock(&lock1); <span class="comment">// 解锁</span></span><br><span class="line">pthread_mutex_destroy(&lock1); <span class="comment">// 释放</span></span><br></pre></td></tr></table></figure></p><h4 id="NSLock-再熟悉不过的吧，遵循NSLocking协议"><a href="#NSLock-再熟悉不过的吧，遵循NSLocking协议" class="headerlink" title="NSLock: 再熟悉不过的吧，遵循NSLocking协议"></a>NSLock: 再熟悉不过的吧，遵循NSLocking协议</h4> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">NSLock</span> *aLock = [[<span class="built_in">NSLock</span> alloc] init];</span><br><span class="line">[aLock lock];</span><br><span class="line">[aLock unlock]; </span><br><span class="line">[aLock tryLock]; <span class="comment">// 尝试加锁 返回Bool</span></span><br><span class="line">[aLock lockBeforeDate: <span class="built_in">NSDate</span>.date]; <span class="comment">// 能否在指定时间点之前获取锁</span></span><br></pre></td></tr></table></figure><h4 id="NSCondition-互斥锁，遵循NSLocking协议"><a href="#NSCondition-互斥锁，遵循NSLocking协议" class="headerlink" title="NSCondition: 互斥锁，遵循NSLocking协议"></a>NSCondition: 互斥锁，遵循NSLocking协议</h4><p> 存在虚假唤醒问题，</p><figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br></pre></td><td class="code"><pre><span class="line">- (<span class="type">void</span>)testConditionLock {</span><br><span class="line"> <span class="keyword">for</span> (<span class="type">int</span> i = <span class="number">0</span>; i < <span class="number">50</span>; i ++) {</span><br><span class="line"> <span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> [<span class="keyword">self</span> testProduction];</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">for</span> (<span class="type">int</span> i = <span class="number">0</span>; i < <span class="number">100</span>; i ++) {</span><br><span class="line"> <span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> [<span class="keyword">self</span> testConsumption];</span><br><span class="line"> });</span><br><span class="line"> }</span><br><span class="line">}</span><br><span class="line">- (<span class="type">void</span>)testProduction {</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock lock]; <span class="comment">// 加锁</span></span><br><span class="line"> <span class="keyword">self</span>.count ++;</span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"生产了一个, 现有还有 %d 个"</span>, <span class="keyword">self</span>.count);</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock signal]; <span class="comment">// 唤醒一个正在休眠的线程，如果要唤醒多个，需要调用多次。如果没有符合条件的线程则什么也不做。使用时必须已加锁。</span></span><br><span class="line"> [<span class="keyword">self</span>.conditionLock unlock]; <span class="comment">// 解锁</span></span><br><span class="line">}</span><br><span class="line">- (<span class="type">void</span>)testConsumption {</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock lock]; <span class="comment">// 加锁</span></span><br><span class="line"> <span class="keyword">while</span> (<span class="keyword">self</span>.count == <span class="number">0</span>) { </span><br><span class="line"> <span class="comment">// 使用while而非if，是用于解决虚假唤醒（一次signal唤醒多个wait）问题，</span></span><br><span class="line"> <span class="comment">// 即当次线程被唤醒则再去检查count个数是否有值，否则继续进入wait状态，</span></span><br><span class="line"> <span class="comment">// 这样也就被唤醒多个的线程只有一个能正常走出此while循环进入下一步消耗的步骤</span></span><br><span class="line"> [<span class="keyword">self</span>.iCondition wait]; <span class="comment">// 阻塞当前线程，使线程进入休眠，等待唤醒信号。使用时必须已加锁</span></span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">self</span>.count --;</span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"消耗了一个, 现有还有 %d 个"</span>, <span class="keyword">self</span>.count);</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock unlock]; <span class="comment">// 解锁</span></span><br><span class="line">}</span><br></pre></td></tr></table></figure><h4 id="NSConditionLock：互斥锁，遵循NSLocking协议"><a href="#NSConditionLock：互斥锁，遵循NSLocking协议" class="headerlink" title="NSConditionLock：互斥锁，遵循NSLocking协议"></a>NSConditionLock：互斥锁，遵循NSLocking协议</h4><figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line">var conditionLock = [[<span class="built_in">NSConditionLock</span> alloc] initWithCondition:<span class="number">10</span>]; </span><br><span class="line"><span class="comment">// 初始化，默认给一个条件</span></span><br><span class="line"><span class="comment">// 加锁: 当lockWhenCondition的条件满足当前锁的条件时加锁，比如下面的10，等于初始时的条件10</span></span><br><span class="line"><span class="comment">// 解锁: unlockWithCondition，重置锁的条件，</span></span><br><span class="line"><span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock lockWhenCondition:<span class="number">10</span>]; <span class="comment">// 满足匹配条件时加锁</span></span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"线程 1"</span>);</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock unlockWithCondition:<span class="number">2</span>]; <span class="comment">// 解锁, 并重置条件</span></span><br><span class="line">});</span><br><span class="line"><span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock lockWhenCondition:<span class="number">2</span>]; <span class="comment">// 满足匹配条件时加锁</span></span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"线程 2"</span>);</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock unlockWithCondition:<span class="number">1</span>]; <span class="comment">// 解锁, 并重置条件</span></span><br><span class="line">});</span><br><span class="line"><span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock lockWhenCondition:<span class="number">1</span>]; <span class="comment">// 满足匹配条件时加锁</span></span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"线程 3"</span>);</span><br><span class="line"> [<span class="keyword">self</span>.conditionLock unlockWithCondition:<span class="number">0</span>]; <span class="comment">// 解锁, 并重置条件</span></span><br><span class="line">});</span><br></pre></td></tr></table></figure><h4 id="NSRecursiveLock-可重入互斥锁，遵循NSLocking协议"><a href="#NSRecursiveLock-可重入互斥锁，遵循NSLocking协议" class="headerlink" title="NSRecursiveLock: 可重入互斥锁，遵循NSLocking协议"></a>NSRecursiveLock: 可重入互斥锁，遵循NSLocking协议</h4><p> 递归锁，就是字面意思，可以递归加锁加锁加锁 再解锁解锁解锁的锁<br> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> <span class="keyword">static</span> <span class="type">void</span> (^recursiveBlock)(<span class="type">int</span>);</span><br><span class="line"> recursiveBlock = ^(<span class="type">int</span> value){</span><br><span class="line"> <span class="keyword">if</span> (value > <span class="number">0</span>) {</span><br><span class="line"> [<span class="keyword">self</span>.recursiveLock lock]; <span class="comment">// 加锁</span></span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"value: %d"</span>, value);</span><br><span class="line"> recursiveBlock(value - <span class="number">1</span>);</span><br><span class="line"> [<span class="keyword">self</span>.recursiveLock unlock]; <span class="comment">// 解锁</span></span><br><span class="line"> }</span><br><span class="line"> };</span><br><span class="line"> recursiveBlock(<span class="number">10</span>);</span><br><span class="line">});</span><br></pre></td></tr></table></figure></p><h4 id="synchronized-可重入互斥锁，最简单的锁"><a href="#synchronized-可重入互斥锁，最简单的锁" class="headerlink" title="@synchronized: 可重入互斥锁，最简单的锁"></a>@synchronized: 可重入互斥锁，最简单的锁</h4> <figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"> <span class="built_in">dispatch_async</span>(dispatch_get_global_queue(<span class="number">0</span>, <span class="number">0</span>), ^{</span><br><span class="line"> <span class="keyword">static</span> <span class="type">void</span> (^recursiveBlock)(<span class="type">int</span>);</span><br><span class="line"> recursiveBlock = ^(<span class="type">int</span> value){</span><br><span class="line"> <span class="keyword">@synchronized</span> (<span class="keyword">self</span>) {</span><br><span class="line"> <span class="keyword">if</span> (value > <span class="number">0</span>) {</span><br><span class="line"> <span class="built_in">NSLog</span>(<span class="string">@"value: %d"</span>, value);</span><br><span class="line"> recursiveBlock(value - <span class="number">1</span>);</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line"> };</span><br><span class="line"> recursiveBlock(<span class="number">10</span>);</span><br><span class="line">});</span><br></pre></td></tr></table></figure><h4 id="读写锁：也称“共享-互斥锁”、多读者-单写者锁"><a href="#读写锁：也称“共享-互斥锁”、多读者-单写者锁" class="headerlink" title="读写锁：也称“共享-互斥锁”、多读者-单写者锁"></a>读写锁：也称“共享-互斥锁”、多读者-单写者锁</h4><p> 读操作可并发重入，写操作是互斥的，而且读和写的操作也是互斥的。</p><ul><li><p>同一时刻要么写的操作，要么读的操作。</p></li><li><p>若是写，则最多只能有一个线程在写；若是读，则可以多个线程同时进行读</p><figure class="highlight objc"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 并发队列，因为需要多读</span></span><br><span class="line"><span class="built_in">dispatch_queue_t</span> queue = dispatch_queue_create(<span class="string">"pushLock"</span>, DISPATCH_QUEUE_CONCURRENT);</span><br><span class="line"><span class="comment">// 读操作，同步可以直接获取结果</span></span><br><span class="line"><span class="built_in">dispatch_sync</span>(queue, ^{</span><br><span class="line"> <span class="comment">// 读操作</span></span><br><span class="line">});</span><br><span class="line"><span class="comment">// 写操作，栅栏函数可以保证此时只有写操作，异步可以避免耗时操作阻塞线程</span></span><br><span class="line">dispatch_barrier_async(queue, ^{</span><br><span class="line"> <span class="comment">// 写操作，可能耗时</span></span><br><span class="line">});</span><br></pre></td></tr></table></figure></li></ul><h3 id="学术名词百科："><a href="#学术名词百科：" class="headerlink" title="学术名词百科："></a>学术名词百科：</h3><p><a href="https://en.wikipedia.org/wiki/Spurious_wakeup">虚假唤醒</a><br><a href="https://zh.wikipedia.org/wiki/%E8%87%AA%E6%97%8B%E9%94%81">自旋锁</a><br><a href="https://zh.wikipedia.org/wiki/%E4%BC%98%E5%85%88%E8%BD%AC%E7%BD%AE">优先级倒置</a></p>]]></content>
<tags>
<tag> iOS </tag>
<tag> Lock </tag>
</tags>
</entry>
<entry>
<title>Flutter 流式布局</title>
<link href="/2022/05/27/f80c8416a26c.html"/>
<url>/2022/05/27/f80c8416a26c.html</url>
<content type="html"><![CDATA[<h1 id="流式布局"><a href="#流式布局" class="headerlink" title="流式布局"></a>流式布局</h1><h3 id="Wrap"><a href="#Wrap" class="headerlink" title="Wrap"></a>Wrap</h3><p>对于Wrap和Flex（包括Row和Column）除了超出显示范围后Wrap会折行外，其它行为基本相同</p><ul><li>spacing：主轴方向子widget的间距</li><li>runSpacing：纵轴方向的间距</li><li>runAlignment：纵轴方向的对齐方式</li></ul><h3 id="Flow"><a href="#Flow" class="headerlink" title="Flow"></a>Flow</h3><p>Flow主要用于一些需要自定义布局策略或性能要求较高(如动画中)的场景</p><span id="more"></span><h5 id="优点："><a href="#优点：" class="headerlink" title="优点："></a>优点：</h5><ul><li>性能好；Flow是一个对子组件尺寸以及位置调整非常高效的控件，Flow用转换矩阵在对子组件进行位置调整的时候进行了优化：在Flow定位过后，如果子组件的尺寸或者位置发生了变化，在FlowDelegate中的paintChildren()方法中调用context.paintChild 进行重绘，而context.paintChild在重绘时使用了转换矩阵，并没有实际调整组件位置。</li><li>灵活；由于我们需要自己实现FlowDelegate的paintChildren()方法，所以我们需要自己计算每一个组件的位置，因此，可以自定义布局策略。<h5 id="缺点："><a href="#缺点：" class="headerlink" title="缺点："></a>缺点：</h5></li><li>使用复杂。</li><li>Flow 不能自适应子组件大小，必须通过指定父容器大小或实现TestFlowDelegate的getSize返回固定大小。</li></ul><p>可以看到我们主要的任务就是实现paintChildren，它的主要任务是确定每个子widget位置。由于Flow不能自适应子widget的大小，我们通过在getSize返回一个固定大小来指定Flow的大小。</p>]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>Flutter 弹性布局</title>
<link href="/2022/05/26/b7fe3f1c9dfb.html"/>
<url>/2022/05/26/b7fe3f1c9dfb.html</url>
<content type="html"><![CDATA[<h1 id="弹性布局-Flex"><a href="#弹性布局-Flex" class="headerlink" title="弹性布局 (Flex)"></a>弹性布局 (Flex)</h1><p>弹性布局允许子组件按照一定比例来分配父容器空间, 主要通过Flex和Expanded来配合实现。</p><h2 id="Flex"><a href="#Flex" class="headerlink" title="Flex"></a>Flex</h2><p>定义, 相比Row、Column多了两个参数, 其实他们都是继承于Flex;</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> Flex({</span><br><span class="line"> <span class="comment">// ...</span></span><br><span class="line"> <span class="keyword">required</span> <span class="keyword">this</span>.direction, <span class="comment">// 布局的方向: 水平、垂直方向</span></span><br><span class="line"> <span class="comment">// ...</span></span><br><span class="line"> <span class="keyword">this</span>.clipBehavior = Clip.none,</span><br><span class="line"> <span class="comment">// ...</span></span><br><span class="line"> })</span><br></pre></td></tr></table></figure><span id="more"></span><h2 id="Expanded"><a href="#Expanded" class="headerlink" title="Expanded"></a>Expanded</h2><p>Expanded 只能作为 Flex 的子组件，它可以按比例“扩伸”Flex子组件所占用的空间。因为 Row 和 Column 都继承自 Flex，所以 Expanded 也可以作为它们的孩子。</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> Expanded({</span><br><span class="line"> Key? key,</span><br><span class="line"> <span class="built_in">int</span> flex = <span class="number">1</span>,</span><br><span class="line"> <span class="keyword">required</span> Widget child,</span><br><span class="line">})</span><br></pre></td></tr></table></figure><p>参数:<br>flex参数为弹性系数，如果为 0 或null，则child是没有弹性的，即不会被扩伸占用的空间。如果大于0，所有的Expanded按照其 flex 的比例来分割主轴的全部剩余空间。</p><h3 id="Spacer"><a href="#Spacer" class="headerlink" title="Spacer"></a>Spacer</h3><p>占用指定比例的剩余空间, 是Expanded的一个包装类</p>]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>Flutter 线性布局</title>
<link href="/2022/05/25/19cb93b3048e.html"/>
<url>/2022/05/25/19cb93b3048e.html</url>
<content type="html"><![CDATA[<h1 id="线性布局-Row、Column"><a href="#线性布局-Row、Column" class="headerlink" title="线性布局 (Row、Column)"></a>线性布局 (Row、Column)</h1><p>Row和Column, 即: 水平方向和垂直方向排列子组件;</p><h3 id="构造方法"><a href="#构造方法" class="headerlink" title="构造方法"></a>构造方法</h3><p>两个轴向:</p><ul><li>mainAxis: 主轴, 即本组件主体的方向</li><li>crossAxis: 纵轴, 即垂直于主轴的方向</li></ul><span id="more"></span><h4 id="Row"><a href="#Row" class="headerlink" title="Row"></a>Row</h4><p>主轴: 水平方向</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> Row({</span><br><span class="line"> Key? key,</span><br><span class="line"> MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,</span><br><span class="line"> MainAxisSize mainAxisSize = MainAxisSize.max,</span><br><span class="line"> CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,</span><br><span class="line"> TextDirection? textDirection,</span><br><span class="line"> VerticalDirection verticalDirection = VerticalDirection.down,</span><br><span class="line"> TextBaseline? textBaseline, <span class="comment">// NO DEFAULT: we don't know what the text's baseline should be</span></span><br><span class="line"> <span class="built_in">List</span><Widget> children = <span class="keyword">const</span> <Widget>[],</span><br><span class="line"> })</span><br></pre></td></tr></table></figure><h4 id="Column"><a href="#Column" class="headerlink" title="Column"></a>Column</h4><p>主轴: 垂直方向</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> Column({</span><br><span class="line"> Key? key,</span><br><span class="line"> MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,</span><br><span class="line"> MainAxisSize mainAxisSize = MainAxisSize.max,</span><br><span class="line"> CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,</span><br><span class="line"> TextDirection? textDirection,</span><br><span class="line"> VerticalDirection verticalDirection = VerticalDirection.down,</span><br><span class="line"> TextBaseline? textBaseline,</span><br><span class="line"> <span class="built_in">List</span><Widget> children = <span class="keyword">const</span> <Widget>[],</span><br><span class="line"> })</span><br></pre></td></tr></table></figure><p>可以发现构造方法基本一样, 接下来看下具体参数的作用</p><h3 id="参数大致含义"><a href="#参数大致含义" class="headerlink" title="参数大致含义"></a>参数大致含义</h3><ul><li>mainAxisAlignment: 表示子组件在主轴(Row为水平方向)的对齐方式, 参考系textDirection<ul><li>.start: 表示沿textDirection阅读方向的初始方向对齐</li><li>.end: 和.start正好相反</li><li>.center: 表示居中对齐</li><li>.spaceBetween: 平均分控件之间 0:x:x:0</li><li>.spaceAround: 平均分周围 x:xx:xx:x</li><li>.spaceEvenly: 平均分所有间隙 x:x:x:x</li></ul></li><li>mainAxisSize: 表示在主轴(Row为水平方向)的占用空间<ul><li>.max: 表示尽可能多的占用水平方向的空间，此时无论子 widgets 实际占用多少水平空间，Row的宽度始终等于水平方向的最大宽度；</li><li>.min: 表示尽可能少的占用水平空间，当子组件没有占满水平剩余空间，则Row的实际宽度等于所有子组件占用的的水平空间；</li></ul></li><li>crossAxisAlignment: 表示子组件在纵轴(Row为垂直方向)的对齐方式, 高度等于子组件高度中最大值, 参考系是verticalDirection<ul><li>.start</li><li>.end</li><li>.center</li><li>.stretch</li><li>.baseline</li></ul></li><li>textDirection: 表示主轴(Row为水平)的布局方向(阅读方向)<ul><li>.ltr: 中文、英语</li><li>.rtl: 阿拉伯语、Hebrew</li></ul></li><li>verticalDirection: 表示纵轴(Row为垂直)的布局方向<ul><li>.up: 表示从底部到顶部, start在底部</li><li>.down: 表示从顶部到底部, start在顶部</li></ul></li><li>textBaseline: 基线对齐</li><li>children: 子组件数组</li></ul><h3 id="demo"><a href="#demo" class="headerlink" title="demo"></a>demo</h3><p>Row和Column都只会在主轴方向占用尽可能大的空间，而纵轴的长度则取决于子组件长度中最大的, 比如在Row的高度, Column的宽度等</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br></pre></td><td class="code"><pre><span class="line">Column(</span><br><span class="line"> <span class="comment">// 排除纵轴的默认居中对齐的干扰</span></span><br><span class="line"> crossAxisAlignment: CrossAxisAlignment.start,</span><br><span class="line"> children: <Widget>[</span><br><span class="line"> Row(</span><br><span class="line"> <span class="comment">// RTL.start</span></span><br><span class="line"> mainAxisAlignment: MainAxisAlignment.start,</span><br><span class="line"> textDirection: TextDirection.rtl,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" RTL "</span>),</span><br><span class="line"> Text(<span class="string">" 主轴.start "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> Row(</span><br><span class="line"> <span class="comment">// LTR.start</span></span><br><span class="line"> mainAxisAlignment: MainAxisAlignment.start,</span><br><span class="line"> textDirection: TextDirection.ltr,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" LTR "</span>),</span><br><span class="line"> Text(<span class="string">" 主轴.start "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> Container(</span><br><span class="line"> color: Colors.green, <span class="comment">// 设置一个颜色</span></span><br><span class="line"> child: Row(</span><br><span class="line"> <span class="comment">// 宽度为最小值, 对齐无效果</span></span><br><span class="line"> mainAxisSize: MainAxisSize.min,</span><br><span class="line"> mainAxisAlignment: MainAxisAlignment.center,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" AxisSize.min "</span>),</span><br><span class="line"> Text(<span class="string">" 主轴.center "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line"> Container(</span><br><span class="line"> color: Colors.cyan, <span class="comment">// 设置一个颜色</span></span><br><span class="line"> child: Row(</span><br><span class="line"> <span class="comment">// 宽度为最大值, 对齐有效果</span></span><br><span class="line"> mainAxisSize: MainAxisSize.max,</span><br><span class="line"> mainAxisAlignment: MainAxisAlignment.center,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" AxisSize.max "</span>),</span><br><span class="line"> Text(<span class="string">" 主轴.center "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line"> Row(</span><br><span class="line"> <span class="comment">// 纵轴 由下向上布局， 开头对齐</span></span><br><span class="line"> crossAxisAlignment: CrossAxisAlignment.start,</span><br><span class="line"> verticalDirection: VerticalDirection.up,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" 纵轴.start "</span>),</span><br><span class="line"> Text(<span class="string">" vertical.up "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>, style: TextStyle(fontSize: <span class="number">30.0</span>)),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> Row(</span><br><span class="line"> <span class="comment">// 纵轴 由上向下布局， 开头对齐</span></span><br><span class="line"> crossAxisAlignment: CrossAxisAlignment.start,</span><br><span class="line"> verticalDirection: VerticalDirection.down,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" 纵轴.start "</span>),</span><br><span class="line"> Text(<span class="string">" vertical.down "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>, style: TextStyle(fontSize: <span class="number">30.0</span>)),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> Row(</span><br><span class="line"> <span class="comment">// 纵轴 由上向下布局， 居中对齐</span></span><br><span class="line"> crossAxisAlignment: CrossAxisAlignment.center,</span><br><span class="line"> verticalDirection: VerticalDirection.down,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" 纵轴.center "</span>),</span><br><span class="line"> Text(<span class="string">" vertical.down "</span>),</span><br><span class="line"> Text(<span class="string">" Hello "</span>, style: TextStyle(fontSize: <span class="number">30.0</span>)),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> ],</span><br><span class="line">);</span><br></pre></td></tr></table></figure><p>效果</p><img src="/2022/05/25/19cb93b3048e/16535503798437.jpg" class=""><p>如果Row里面嵌套Row，或者Column里面再嵌套Column，那么只有最外面的Row或Column会占用尽可能大的空间，里面Row或Column所占用的空间为实际大小</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br></pre></td><td class="code"><pre><span class="line">Container(</span><br><span class="line"> color: Colors.blue,</span><br><span class="line"> child: Padding(</span><br><span class="line"> padding: <span class="keyword">const</span> EdgeInsets.all(<span class="number">16.0</span>),</span><br><span class="line"> child: Row(</span><br><span class="line"> mainAxisSize: MainAxisSize.max,</span><br><span class="line"> children: <Widget>[</span><br><span class="line"> Container(</span><br><span class="line"> color: Colors.orange,</span><br><span class="line"> child: Row(</span><br><span class="line"> mainAxisSize: MainAxisSize.max,</span><br><span class="line"> children: <span class="keyword">const</span> <Widget>[</span><br><span class="line"> Text(<span class="string">" Hello "</span>),</span><br><span class="line"> Text(<span class="string">" World "</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> )</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><p>效果:</p><img src="/2022/05/25/19cb93b3048e/16535497718012.jpg" class="">]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>LLDB</title>
<link href="/2022/05/24/284708204981.html"/>
<url>/2022/05/24/284708204981.html</url>
<content type="html"><![CDATA[<h1 id="LLDB"><a href="#LLDB" class="headerlink" title="LLDB"></a>LLDB</h1><ul><li><code>po</code>: 为 print object 的缩写，显示对象的文本描述, <code>expression -O</code>的别称</li><li><code>bt</code>: 打印当前堆栈信息</li><li><code>register read xx</code>: 读取寄存器</li><li><code>memory read/个数+格式+每个地址单元的长度 内存地址</code> 查看内存数据<ul><li>默认为：memory read/16xb</li><li><code>格式</code>: x-16进制、f-浮点数，d-10进制，u-10进制无符号，o-8进制，t-2进制<br> a-16进制格式+实际地址类型，i-指令地址格式，c-按字符格式</li><li><code>字节数</code>: b-1个字节，h-2个字节，w-4个字节，g-8个字节。</li><li><code>x = memory read</code> x/16xb</li></ul></li><li><code>memory write 地址 数据</code> 向指定内存写入数据<span id="more"></span>命令格式<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">// 命令 + 子命令 + 命令选项 + 命令参数</span><br><span class="line"><command> [<subcom> [<subcom>...]] <action> [-options [optionvalue]] [arg [arg...]]</span><br></pre></td></tr></table></figure><h2 id="常用命令"><a href="#常用命令" class="headerlink" title="常用命令"></a>常用命令</h2></li></ul><h3 id="expression"><a href="#expression" class="headerlink" title="expression"></a>expression</h3><p>执行表达式并将表达式的执行结果输出打印。开发中常用po来打印对象，po实际上就是expression -O的别名。</p><h3 id="breakpoint"><a href="#breakpoint" class="headerlink" title="breakpoint"></a>breakpoint</h3><p>代码调试断点</p><h5 id="指定文件和行号设置断点："><a href="#指定文件和行号设置断点：" class="headerlink" title="指定文件和行号设置断点："></a>指定文件和行号设置断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">breakpoint set --file easeapi.c --line 12</span><br><span class="line">breakpoint set -f ViewController.m -l 12</span><br></pre></td></tr></table></figure><h5 id="指定函数名称设置断点："><a href="#指定函数名称设置断点：" class="headerlink" title="指定函数名称设置断点："></a>指定函数名称设置断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">//对于C函数，填写完整的函数名称。</span><br><span class="line">breakpoint set --name easeapi_func</span><br><span class="line">breakpoint set -n easeapi_func</span><br><span class="line"></span><br><span class="line">//对于Objective-C函数，填写完整的方法签名Selector字符串。</span><br><span class="line">breakpoint set -n viewDidAppear:</span><br><span class="line">breakpoint set -n tableView:cellForRowAtIndexPath:</span><br><span class="line"></span><br><span class="line">//对于Swift方法，填写函数名称，参数省略。</span><br><span class="line">breakpoint set -n easeapi_func</span><br></pre></td></tr></table></figure><h5 id="指定对象方法设置断点："><a href="#指定对象方法设置断点：" class="headerlink" title="指定对象方法设置断点："></a>指定对象方法设置断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">breakpoint set -n "-[ViewController viewDidAppear:]"</span><br><span class="line">breakpoint set -n "+[ViewController classFunc]"</span><br><span class="line">//Swift函数</span><br><span class="line">breakpoint set -n "ViewController.easeapi_func"</span><br></pre></td></tr></table></figure><h5 id="指定代码地址设置断点："><a href="#指定代码地址设置断点：" class="headerlink" title="指定代码地址设置断点："></a>指定代码地址设置断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">breakpoint set --address 0x1021744bb</span><br><span class="line">breakpoint set -a 0x1021744bb</span><br></pre></td></tr></table></figure><h5 id="查看已设置的断点"><a href="#查看已设置的断点" class="headerlink" title="查看已设置的断点"></a>查看已设置的断点</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">breakpoint list</span><br></pre></td></tr></table></figure><p>每一次设置的断点都是逻辑断点（对应编号1、2、3等），一个逻辑断点可以解析为多个断点位置（对应编号1.1等）</p><h5 id="取消断点"><a href="#取消断点" class="headerlink" title="取消断点"></a>取消断点</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">breakpoint delete 断点编号</span><br></pre></td></tr></table></figure><p>若不加编号则为所有断点</p><h4 id="watchpoint"><a href="#watchpoint" class="headerlink" title="watchpoint"></a>watchpoint</h4><p>内存调试断点</p><h5 id="设置观察变量："><a href="#设置观察变量：" class="headerlink" title="设置观察变量："></a>设置观察变量：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">watchpoint set variable value</span><br><span class="line">watchpoint set variable self->_dataArray //不能使用点语法</span><br></pre></td></tr></table></figure><h5 id="设置观察内存地址："><a href="#设置观察内存地址：" class="headerlink" title="设置观察内存地址："></a>设置观察内存地址：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">watchpoint set expression 0x000000016f47fc70</span><br></pre></td></tr></table></figure><h5 id="查看所有内存断点："><a href="#查看所有内存断点：" class="headerlink" title="查看所有内存断点："></a>查看所有内存断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">watchpoint list</span><br></pre></td></tr></table></figure><h5 id="删除内存断点："><a href="#删除内存断点：" class="headerlink" title="删除内存断点："></a>删除内存断点：</h5><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">watchpoint delete index</span><br><span class="line">watchpoint delete</span><br></pre></td></tr></table></figure><h3 id="register"><a href="#register" class="headerlink" title="register"></a>register</h3><p>寄存器操作</p><p><code>register read</code> 读取所有寄存器<br>ARM64架构中共有34个寄存器，包括31个通用寄存器、SP、PC、CPSR。</p><ul><li>通用寄存器<ul><li>r0 - r30是31个通用寄存器，每个寄存器可以存取一个64位大小的数。 </li><li>当使用x0 - x30访问时，它就是一个64位的数。</li><li>当使用w0 - w30访问时，是这些寄存器的低32位。 </li><li>r29又称FP寄存器(frame point)，主要用来保存栈帧（栈底）指针。 </li><li>r30又称LR寄存器(link register)，主要用来保存函数返回地址。</li></ul></li><li>SP：stack pointer，栈顶指针；</li><li>PC：用来记录当前执行的指令地址；</li><li>CPSR：状态寄存器。</li></ul><p>读取指定寄存器的值：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">register read x1</span><br></pre></td></tr></table></figure><p>写入寄存器：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">register write x0 1</span><br></pre></td></tr></table></figure><h3 id="memory"><a href="#memory" class="headerlink" title="memory"></a>memory</h3><p>内存操作</p><h4 id="从内存读取数据"><a href="#从内存读取数据" class="headerlink" title="从内存读取数据"></a>从内存读取数据</h4><p><code>memory read/个数+格式+每个地址单元的长度 内存地址</code></p><ul><li>默认为：memory read/16xb</li><li><code>格式</code>: x-16进制、f-浮点数，d-10进制，u-10进制无符号，o-8进制，t-2进制；<br> a-16进制格式+实际地址类型，i-指令地址格式，c-按字符格式</li><li><code>字节数</code>: b-1个字节，h-2个字节，w-4个字节，g-8个字节。</li></ul><p>等价于 <code>x/16xb = memory read/16xb</code></p><h4 id="往内存写入数据"><a href="#往内存写入数据" class="headerlink" title="往内存写入数据"></a>往内存写入数据</h4><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">memory write 地址 数据</span><br><span class="line">//以8字节对齐，写入两个数据</span><br><span class="line">memory write 0x000000016f08fc70 -s 8 0x01 0x02</span><br></pre></td></tr></table></figure><h3 id="image"><a href="#image" class="headerlink" title="image"></a>image</h3><p>image镜像文件操作</p><p>查看已经加载的Image</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">image list</span><br></pre></td></tr></table></figure><p>查看信息</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">//查找类信息</span><br><span class="line">image lookup --type UIViewController</span><br><span class="line">image lookup -t UIViewController</span><br><span class="line">//查找符号</span><br><span class="line">image lookup --name viewDidLoad</span><br><span class="line">image lookup -n viewDidLoad</span><br><span class="line">//查找地址</span><br><span class="line">image lookup --address 0x000000018ff60490</span><br><span class="line">image lookup -a 0x000000018ff60490</span><br></pre></td></tr></table></figure><p>导出image信息：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">//导出所有sections信息</span><br><span class="line">image dump sections</span><br><span class="line">//导出所有符号信息</span><br><span class="line">image dump symtab</span><br></pre></td></tr></table></figure><h3 id="thread"><a href="#thread" class="headerlink" title="thread"></a>thread</h3><p>线程操作</p><p>查看线程列表<br><code>thread list</code><br>其中，使用*标记当前线程；使用#标记线程编号。</p><p>获取线程调用栈：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">//获取当前线程调用栈</span><br><span class="line">thread backtrace</span><br><span class="line">//函数的堆栈</span><br><span class="line">bt</span><br><span class="line">//获取所有线程调用栈</span><br><span class="line">thread backtrace all</span><br></pre></td></tr></table></figure><p>在Xcode中，有四个控制Debug的按钮：</p><ul><li>Continue：程序继续运行<br> <code>thread continue/continue/c</code></li><li>Step over：单步指定，遇到子函数时断点不会进入子函数。<br> <code>thread step-over/next/n</code></li><li>Step into：单步运行，遇到子函数时断点会进入子函数。<br> <code>thread step-into/step/s</code></li><li>Step out：执行完当前函数剩余的代码，返回上一层函数。<br> <code>thread step-out/finish</code></li></ul><p>修改函数返回：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">thread return 10</span><br></pre></td></tr></table></figure><h3 id="frame"><a href="#frame" class="headerlink" title="frame"></a>frame</h3><p>栈帧信息<br>查看当前栈帧变量：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">frame variable</span><br></pre></td></tr></table></figure><h3 id="disassemble"><a href="#disassemble" class="headerlink" title="disassemble"></a>disassemble</h3><p>显示汇编代码<br>使用d/di/dis同等效果。</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">disassemble -b</span><br><span class="line">disassemble --frame</span><br><span class="line">disassemble --name func_name</span><br><span class="line">disassemble -a address</span><br><span class="line">disassemble -s address</span><br></pre></td></tr></table></figure>]]></content>
<tags>
<tag> Xcode </tag>
<tag> iOS </tag>
<tag> LLDB </tag>
</tags>
</entry>
<entry>
<title>Flutter 布局约束</title>
<link href="/2022/05/24/11406298780d.html"/>
<url>/2022/05/24/11406298780d.html</url>
<content type="html"><![CDATA[<h1 id="布局约束"><a href="#布局约束" class="headerlink" title="布局约束"></a>布局约束</h1><p>Flutter 中有两种布局模型：</p><ul><li>基于 RenderBox 的盒模型布局。</li><li>基于 Sliver ( RenderSliver ) 按需加载列表布局。</li></ul><p>大致布局流程如下：</p><ol><li>上层组件向下层组件传递约束（constraints）条件。</li><li>下层组件确定自己的大小，然后告诉上层组件。注意下层组件的大小必须符合父组件的约束。</li><li>上层组件确定下层组件相对于自身的偏移和确定自身的大小（大多数情况下会根据子组件的大小来确定自身的大小）。</li></ol><p><code>因为任何时候子组件都必须先遵守父组件的约束</code></p><span id="more"></span><p>盒模型布局组件有两个特点：</p><ol><li>组件对应的渲染对象都继承自 RenderBox 类。在本书后面文章中如果提到某个组件是 RenderBox，则指它是基于盒模型布局的，而不是说组件是 RenderBox 类的实例。</li><li>在布局过程中父级传递给子级的约束信息由 BoxConstraints 描述。</li></ol><h3 id="BoxConstraints-父-gt-子-的约束信息"><a href="#BoxConstraints-父-gt-子-的约束信息" class="headerlink" title="BoxConstraints (父->子)的约束信息"></a>BoxConstraints (父->子)的约束信息</h3><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> BoxConstraints({</span><br><span class="line"> <span class="keyword">this</span>.minWidth = <span class="number">0.0</span>, <span class="comment">//最小宽度</span></span><br><span class="line"> <span class="keyword">this</span>.maxWidth = <span class="built_in">double</span>.infinity, <span class="comment">//最大宽度</span></span><br><span class="line"> <span class="keyword">this</span>.minHeight = <span class="number">0.0</span>, <span class="comment">//最小高度</span></span><br><span class="line"> <span class="keyword">this</span>.maxHeight = <span class="built_in">double</span>.infinity <span class="comment">//最大高度</span></span><br><span class="line">})</span><br></pre></td></tr></table></figure><p>BoxConstraints.tight(Size size)，它可以生成固定宽高的限制；<br>BoxConstraints.expand()可以生成一个尽可能大的用以填充另一个容器的BoxConstraints;</p><h3 id="ConstrainedBox"><a href="#ConstrainedBox" class="headerlink" title="ConstrainedBox"></a>ConstrainedBox</h3><p>通过约束限制子组件大小的组件</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 临时定义一个</span></span><br><span class="line">Widget yellowBox = <span class="keyword">const</span> DecoratedBox(</span><br><span class="line"> decoration: BoxDecoration(color: Colors.yellow),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">Widget testConstrainedBox() {</span><br><span class="line"> <span class="keyword">return</span> ConstrainedBox( <span class="comment">// 父组件</span></span><br><span class="line"> constraints: <span class="keyword">const</span> BoxConstraints( <span class="comment">// 父组件对子组件的 约束信息</span></span><br><span class="line"> minWidth: <span class="built_in">double</span>.infinity, <span class="comment">// 宽度尽可能大</span></span><br><span class="line"> minHeight: <span class="number">80.0</span> <span class="comment">// 最小高度为80像素</span></span><br><span class="line"> ),</span><br><span class="line"> child: SizedBox( <span class="comment">// 子组件</span></span><br><span class="line"> height: <span class="number">20.0</span>, <span class="comment">// 虽然20小于80， 但是父组件约束了最小为80</span></span><br><span class="line"> child: yellowBox,</span><br><span class="line"> ),</span><br><span class="line"> );</span><br><span class="line">}</span><br></pre></td></tr></table></figure><p>效果</p><img src="/2022/05/24/11406298780d/16533793465334.jpg" class=""> <p>虽然自组件设置的高是20, 但是父组件约束了最小为80, 所以高度是80</p><h4 id="SizedBox"><a href="#SizedBox" class="headerlink" title="SizedBox"></a>SizedBox</h4><p>SizedBox只是ConstrainedBox的一个定制,</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line">SizedBox(width: <span class="number">80.0</span>, height: <span class="number">80.0</span>, child: yellowBox)</span><br><span class="line"><span class="comment">// 等价于 </span></span><br><span class="line">ConstrainedBox(</span><br><span class="line"> constraints: BoxConstraints.tightFor(width: <span class="number">80.0</span>, height: <span class="number">80.0</span>),</span><br><span class="line"> child: yellowBox, </span><br><span class="line">)</span><br><span class="line"><span class="comment">// 又等价于</span></span><br><span class="line">ConstrainedBox(</span><br><span class="line"> constraints: BoxConstraints(minHeight: <span class="number">80.0</span>, maxHeight: <span class="number">80.0</span>, minWidth: <span class="number">80.0</span>, maxWidth: <span class="number">80.0</span>),</span><br><span class="line"> child: yellowBox, </span><br><span class="line">)</span><br></pre></td></tr></table></figure><img src="/2022/05/24/11406298780d/16533795446838.jpg" class=""><p>其实<code>ConstrainedBox</code>和<code>SizedBox</code>都是通过<code>RenderConstrainedBox</code>来渲染的;</p><h4 id="多层约束"><a href="#多层约束" class="headerlink" title="多层约束"></a>多层约束</h4><p>如果使用多层ConstrainedBox父组件 会是什么情况呢?</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 外小 内大</span></span><br><span class="line">ConstrainedBox( <span class="comment">// 祖父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">140.0</span>, minHeight: <span class="number">40.0</span>),</span><br><span class="line"> child: ConstrainedBox( <span class="comment">// 父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">180.0</span>, minHeight: <span class="number">80.0</span>),</span><br><span class="line"> child: yellowBox, <span class="comment">// 子组件</span></span><br><span class="line"> ),</span><br><span class="line">);</span><br><span class="line"><span class="comment">// 外大 内小</span></span><br><span class="line">ConstrainedBox( <span class="comment">// 祖父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">180.0</span>, minHeight: <span class="number">80.0</span>),</span><br><span class="line"> child: ConstrainedBox( <span class="comment">// 父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">140.0</span>, minHeight: <span class="number">40.0</span>),</span><br><span class="line"> child: yellowBox, <span class="comment">// 子组件</span></span><br><span class="line"> ),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><img src="/2022/05/24/11406298780d/16533807548379.jpg" class=""><p>因为约束条件是用来约束子组件的</p><ul><li>一层约束时很好理解, 即: <code>maxSize >= 最终大小 && 最终大小 >= minSize</code></li><li>那两层也不难理解, 只要两层约束条件都满足即可: <figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// maxSize1 >= 最终大小 && 最终大小 >= minSize1</span></span><br><span class="line"><span class="comment">// &&</span></span><br><span class="line"><span class="comment">// maxSize2 >= 最终大小 && 最终大小 >= minSize2</span></span><br><span class="line"><span class="comment">// 整理即可得出 </span></span><br><span class="line"><span class="comment">// min(maxSize1, maxSize2) >= 最终大小 >= max(minSize1, minSize2)</span></span><br></pre></td></tr></table></figure></li></ul><h3 id="UnconstrainedBox"><a href="#UnconstrainedBox" class="headerlink" title="UnconstrainedBox"></a>UnconstrainedBox</h3><p>虽然任何时候子组件都必须遵守其父组件的约束，但前提条件是它们必须是父子关系，</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">ConstrainedBox( <span class="comment">// 曾祖父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">180.0</span>, minHeight: <span class="number">80.0</span>), <span class="comment">// 曾祖父组件约束</span></span><br><span class="line"> child: UnconstrainedBox( <span class="comment">// 祖父组件, “去除”曾祖父组件的约束</span></span><br><span class="line"> child: ConstrainedBox( <span class="comment">// 父组件</span></span><br><span class="line"> constraints: BoxConstraints(minWidth: <span class="number">80.0</span>, minHeight: <span class="number">30.0</span>), <span class="comment">// 父组件约束</span></span><br><span class="line"> child: yellowBox, <span class="comment">// 子组件</span></span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line">);</span><br></pre></td></tr></table></figure><img src="/2022/05/24/11406298780d/16533826173981.jpg" class=""><p><strong>任何时候子组件都必须遵守其父组件的约束</strong></p><p>需要注意，UnconstrainedBox 虽然在其子组件布局时可以取消约束（子组件可以为无限大），但是 UnconstrainedBox 自身是受其父组件约束的，所以当 UnconstrainedBox 随着其子组件变大后，如果UnconstrainedBox 的大小超过它父组件约束时，也会导致溢出报错!</p><h3 id="其他约束类"><a href="#其他约束类" class="headerlink" title="其他约束类"></a>其他约束类</h3><p>还有一些其他的尺寸限制类容器</p><ul><li><code>AspectRatio</code> 它可以指定子组件的长宽比、</li><li><code>LimitedBox</code> 用于指定最大宽高、</li><li><code>FractionallySizedBox</code> 可以根据父容器宽高的百分比来设置子组件宽高等</li></ul>]]></content>
<tags>
<tag> iOS </tag>
<tag> Flutter </tag>
<tag> Layout </tag>
</tags>
</entry>
<entry>
<title>复习GCD</title>
<link href="/2022/05/23/be08fa8a65d5.html"/>
<url>/2022/05/23/be08fa8a65d5.html</url>
<content type="html"><![CDATA[<h2 id="队列-FIFO"><a href="#队列-FIFO" class="headerlink" title="队列 FIFO"></a>队列 FIFO</h2><ul><li>串行队列</li><li>并发队列</li><li>全局并发队列</li><li>主队列</li></ul><p>队列只是用来存储任务，没有能力去调度任务</p><span id="more"></span><h2 id="任务"><a href="#任务" class="headerlink" title="任务"></a>任务</h2><ul><li>同步任务 dispatch_sync<ul><li>立即执行、会阻塞当前线程、不具备开辟子线程的能力</li><li>没有线程相关的操作、没有保存任务、立即执行了任务</li></ul></li><li>异步任务 dispatch_async<ul><li>开辟子线程、不会立即执行、不会阻塞当前线程</li><li>保存block、函数式编程、有线程相关的操作</li></ul></li></ul><p>死锁： 在当前线程同步的向串行队列里面添加任务，当前线程锁执行的任务是从当前队列里取出来的</p>]]></content>
<tags>
<tag> iOS </tag>
<tag> GCD </tag>
</tags>
</entry>
<entry>
<title>编译Objc4-838</title>
<link href="/2022/05/08/e233db870454.html"/>
<url>/2022/05/08/e233db870454.html</url>
<content type="html"><![CDATA[<h1 id="编译Objc源码"><a href="#编译Objc源码" class="headerlink" title="编译Objc源码"></a>编译Objc源码</h1><p>要诀:<br>能删则删, 不确定先注释,<br>需加须加, 能设置就设置.</p><h1 id="准备工作"><a href="#准备工作" class="headerlink" title="准备工作"></a>准备工作</h1><p>本次编译<code>objc4-838</code>源码, 即对应<code>macOS 12.2</code>, 高版本未尝试, 理论上大版本一致可行<br>以下相关源码均可在<a href="https://opensource.apple.com/releases/">Apple Open Source</a>中 <code>macOS Monterey 12 -> macOS 12.2</code> 分支看到</p><span id="more"></span><p><a href="https://github.com/apple-oss-distributions/objc4/archive/objc4-838.1.tar.gz">objc4-838 下载地址</a> </p><p><a href="https://github.com/apple-oss-distributions/dyld/archive/dyld-941.5.tar.gz">dyld-941.5 下载地址</a></p><p><a href="https://github.com/apple-oss-distributions/Libc/archive/Libc-1506.40.4.tar.gz">Libc-1506.40.4 下载地址</a></p><p><a href="https://github.com/apple-oss-distributions/libclosure/archive/libclosure-79.tar.gz">libclosure-79 下载地址</a></p><p><a href="https://github.com/apple-oss-distributions/libplatform/archive/libplatform-273.40.1.tar.gz">libplatform-273.40.1 下载地址</a></p><p><a href="https://github.com/apple-oss-distributions/libpthread/archive/libpthread-485.60.2.tar.gz">libpthread-485.60.2 下载地址</a></p><p><a href="https://github.com/apple-oss-distributions/xnu/archive/xnu-8019.80.24.tar.gz">xnu-8019.80.24 下载地址</a></p><p>旧版源码下载<br><a href="https://github.com/apple-oss-distributions/Libc/archive/Libc-825.26.tar.gz">Libc-825.26 下载地址</a> 在 <code>OS X Mountain Lion 10.8 -> Mac OS X 10.8.4</code> 分支下</p><p><a href="https://github.com/apple-oss-distributions/libplatform/archive/libplatform-220.100.1.tar.gz">libplatform-220.100.1 下载地址</a>在 <code>macOS Catalina 10.15 -> macOS 10.15.6</code> 分支下</p><h1 id="Project-相关"><a href="#Project-相关" class="headerlink" title="Project 相关"></a>Project 相关</h1><h2 id="修改-Base-SDK"><a href="#修改-Base-SDK" class="headerlink" title="修改 Base SDK"></a>修改 Base SDK</h2><p>在 <code>Project -> Build Setting -> Base SDK</code> 选择为<code>macOS</code></p><img src="/2022/05/08/e233db870454/16520180096055.jpg" class=""><h2 id="选择编译-Targets-为-objc"><a href="#选择编译-Targets-为-objc" class="headerlink" title="选择编译 Targets 为 objc"></a>选择编译 Targets 为 objc</h2><img src="/2022/05/08/e233db870454/16520180485207.jpg" class=""><h1 id="Targets-配置相关"><a href="#Targets-配置相关" class="headerlink" title="Targets 配置相关"></a>Targets 配置相关</h1><h2 id="修改-Script"><a href="#修改-Script" class="headerlink" title="修改 Script"></a>修改 Script</h2><p>在 <code>Targets -> objc -> Build Phases -> Run Script (markgc)</code> 将 <code>macosx.internal</code> 改成 <code>macosx</code></p><img src="/2022/05/08/e233db870454/16520182953780.jpg" class=""><h2 id="编译时-报错"><a href="#编译时-报错" class="headerlink" title="编译时 报错"></a>编译时 报错</h2><p>文件缺失居多, <code>xx file not found</code></p><p>在项目根目录新增一目录, 用来放缺失文件, (名字可以自定义, 比如<code>/common</code>)<br>然后在项目 <code>Targets -> Build Settings -> Header Search Paths</code> 新增 <code>/common</code> 路径：<code>$(SRCROOT)/common</code></p><img src="/2022/05/08/e233db870454/16520025810206.jpg" class=""><ol><li><p><code>'sys/reason.h' file not found</code><br>在<code>xnu</code>源码的<code>/bsd/sys/reason.h</code>目录下载文件<code>reason.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/sys/reason.h</code>目录</p><img src="/2022/05/08/e233db870454/16520057299390.jpg" class=""></li><li><p><code>'os/feature_private.h' file not found</code><br>直接注释即可, 共三处, 其<code>NSObject.mm</code>有两处</p><img src="/2022/05/08/e233db870454/16520190168277.jpg" class=""></li><li><p><code>'mach-o/dyld_priv.h' file not found</code><br>在<code>dyld</code>源码的<code>/include/mach-o/dyld_priv.h</code>目录下载文件<code>dyld_priv.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/mach-o/dyld_priv.h</code>目录</p><img src="/2022/05/08/e233db870454/16520057504672.jpg" class=""><p>然后要此文件添加宏定义：</p><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">#define DYLD_MACOSX_VERSION_10_11 0x000A0B00</span><br><span class="line">#define DYLD_MACOSX_VERSION_10_12 0x000A0C00</span><br><span class="line">#define DYLD_MACOSX_VERSION_10_13 0x000A0D00</span><br><span class="line">#define DYLD_MACOSX_VERSION_10_14 0x000A0E00</span><br></pre></td></tr></table></figure></li><li><p><code>Expected ','</code> 在 <code>/mach-o/dyld_priv.h</code> 文件中<br>移除<code>__API_AVAILABLE(macos(10.14), ios(12.0), watchos(5.0), tvos(12.0), bridgeos(3.0))</code> 中 <code>bridgeos(3.0)</code> 的条件即可</p><img src="/2022/05/08/e233db870454/16520197415089.jpg" class=""></li><li><p><code>'os/lock_private.h' file not found</code><br>在<code>libplatform</code>源码的<code>/private/os/lock_private.h</code>目录下载文件<code>lock_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/lock_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520057891584.jpg" class=""></li><li><p><code>Expected ','</code> 在 <code>/os/lock_private.h</code> 文件中<br>移除<code>__API_AVAILABLE(macos(10.15), ios(13.0), tvos(13.0), watchos(6.0), bridgeos(4.0))</code> 中 <code>bridgeos(4.0)</code> 的条件即可</p><img src="/2022/05/08/e233db870454/16520202025735.jpg" class=""></li><li><p><code>'os/base_private.h' file not found</code><br>在<code>libplatform-220.100.1</code>源码的<code>/private/os/base_private.h</code>目录下载文件<code>base_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/base_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520159895858.jpg" class=""></li><li><p><code>'pthread/tsd_private.h' file not found</code><br>在<code>libpthread</code>源码的<code>/private/pthread/tsd_private.h</code>目录下载文件<code>tsd_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/pthread/tsd_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520160082926.jpg" class=""></li><li><p><code>'System/machine/cpu_capabilities.h' file not found</code><br>在<code>xnu</code>源码的<code>/osfmk/machine/cpu_capabilities.h</code>目录下载文件<code>cpu_capabilities.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/System/machine/cpu_capabilities.h</code>目录</p><img src="/2022/05/08/e233db870454/16520160595511.jpg" class=""></li><li><p><code>'os/tsd.h' file not found</code><br>在<code>xnu</code>源码的<code>libsyscall/os/tsd.h</code>目录下载文件<code>tsd.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/tsd.h</code>目录</p><img src="/2022/05/08/e233db870454/16520160761343.jpg" class=""></li><li><p><code>'pthread/spinlock_private.h' file not found</code><br>在<code>libpthread</code>源码的<code>/private/pthread/spinlock_private.h</code>目录下载文件<code>spinlock_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/pthread/spinlock_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520161190991.jpg" class=""></li><li><p><code>'System/pthread_machdep.h' file not found</code><br>在<code>Libc-825.26</code>源码的<code>/pthreads/pthread_machdep.h</code>目录下载文件<code>pthread_machdep.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/System/pthread_machdep.h</code>目录</p><img src="/2022/05/08/e233db870454/16520161567520.jpg" class=""></li><li><p><code>'CrashReporterClient.h' file not found</code></p></li></ol><ul><li><p>在<code>Libc-825.26</code>源码的<code>/include/CrashReporterClient.h</code>目录下载文件<code>CrashReporterClient.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/CrashReporterClient.h</code>目录</p> <img src="/2022/05/08/e233db870454/16520161828314.jpg" class=""></li><li><p>还未结束, 因为还缺少宏定义, 在 <code>Targets -> objc -> Build Settings -> Preprocessor Macros</code> 中，添加<code>LIBC_NO_LIBCRASHREPORTERCLIENT</code></p> <img src="/2022/05/08/e233db870454/16520040737366.jpg" class=""></li></ul><ol start="14"><li>在 <code>pthread_machdep.h</code> 文件中一个typedef和三个函数, 这些全部注释即可</li></ol><ul><li><p><code>Typedef redefinition with different types ('int' vs 'volatile OSSpinLock' (aka 'volatile int'))</code></p><img src="/2022/05/08/e233db870454/16520210232107.jpg" class=""></li><li><p><code>Static declaration of '_pthread_has_direct_tsd' follows non-static declaration</code></p><img src="/2022/05/08/e233db870454/16520210499881.jpg" class=""></li><li><p><code>Static declaration of '_pthread_getspecific_direct' follows non-static declaration</code></p><img src="/2022/05/08/e233db870454/16520210663906.jpg" class=""></li><li><p><code>Static declaration of '_pthread_setspecific_direct' follows non-static declaration</code></p><img src="/2022/05/08/e233db870454/16520210870245.jpg" class=""></li></ul><ol start="15"><li><p><code>Unknown type name 'uint32_t' 'uint64_t, Use of undeclared identifier 'INT64_C'</code> 在 <code>/llvm-MathExtras.h</code> 文件中<br>导入头文件 <code>#include <cstdint></code> 即可解决</p><img src="/2022/05/08/e233db870454/16520218944361.jpg" class=""></li><li><p><code>Use of undeclared identifier 'dyld_fall_2020_os_versions'</code></p><img src="/2022/05/08/e233db870454/16520219604415.jpg" class=""></li><li><p><code>Use of undeclared identifier 'objc4' 'preoptimizedCaches'</code></p><img src="/2022/05/08/e233db870454/16520220277190.jpg" class=""></li><li><p><code>'objc-shared-cache.h' file not found</code><br>在<code>dyld</code>源码的<code>/include/objc-shared-cache.h</code>目录下载文件<code>objc-shared-cache.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/objc-shared-cache.h</code>目录</p><img src="/2022/05/08/e233db870454/16520162251666.jpg" class=""></li><li><p><code>Use of undeclared identifier 'dyld_platform_version_macOS_10_13'</code></p><img src="/2022/05/08/e233db870454/16520223502584.jpg" class=""></li><li><p><code>Use of undeclared identifier 'dyld_platform_version_macOS_10_11'</code></p><img src="/2022/05/08/e233db870454/16520222826801.jpg" class=""></li><li><p><code>Use of undeclared identifier 'dyld_fall_2018_os_versions'</code> 注释部分判断条件</p><img src="/2022/05/08/e233db870454/16520223139195.jpg" class=""></li><li><p><code>'Block_private.h' file not found</code><br>在<code>libclosure</code>源码的<code>/Block_private.h</code>目录下载文件<code>Block_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/Block_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520163360611.jpg" class=""></li><li><p><code>'Cambria/Traps.h' file not found</code><br>直接注释即可</p><figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// #include <Cambria/Traps.h></span></span><br><span class="line"><span class="comment">// #include <Cambria/Cambria.h></span></span><br></pre></td></tr></table></figure></li><li><p><code>'_simple.h' file not found</code><br>在<code>libplatform</code>源码的<code>/private/_simple.h</code>目录下载文件<code>_simple.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/_simple.h</code>目录</p><img src="/2022/05/08/e233db870454/16520162431797.jpg" class=""></li><li><p><code>'os/linker_set.h' file not found</code><br>在<code>xnu</code>源码的<code>/bsd/sys/linker_set.h</code>目录下载文件<code>linker_set.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/linker_set.h</code>目录</p><img src="/2022/05/08/e233db870454/16520227164945.jpg" class=""></li><li><p><code>'kern/restartable.h' file not found</code><br>在<code>xnu</code>源码的<code>/osfmk/kern/restartable.h</code>目录下载文件<code>restartable.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/kern/restartable.h</code>目录</p><img src="/2022/05/08/e233db870454/16520164250072.jpg" class=""></li><li><p><code>Use of undeclared identifier 'oah_is_current_process_translated' 和 'objc_thread_get_rip'</code> 注释此<code>if</code>分支</p><img src="/2022/05/08/e233db870454/16520228608250.jpg" class=""></li><li><p><code>'os/reason_private.h' file not found</code><br>在<code>xnu</code>源码的<code>/libkern/os/reason_private.h</code>目录下载文件<code>reason_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/reason_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520231987128.jpg" class=""></li><li><p><code>'os/variant_private.h' file not found</code><br>在<code>Libc</code>源码的<code>/os/variant_private.h</code>目录下载文件<code>variant_private.h</code>文件, 拷贝至<code>/common</code>下, 对应<code>/os/variant_private.h</code>目录</p><img src="/2022/05/08/e233db870454/16520232315070.jpg" class=""><p>还要去掉文件里面的 <code>bridgeos 、 bridgeos(4.0)</code> 参数</p></li><li><p><code>Use of undeclared identifier 'dyld_platform_version_bridgeOS_2_0' iOS_10_0 macOS_10_12 tvOS_10_0 watchOS_3_0</code> 注释此<code>if</code>判断</p><img src="/2022/05/08/e233db870454/16520234982550.jpg" class=""></li><li><p><code>'_static_assert' declared as an array with a negative size</code></p><img src="/2022/05/08/e233db870454/16520235358635.jpg" class=""></li></ol><h2 id="链接时-报错"><a href="#链接时-报错" class="headerlink" title="链接时 报错"></a>链接时 报错</h2><ul><li><p><code>Library not found for -lCrashReporterClient</code><br>进入 <code>Targets -> objc -> Build Setting -> Other Linker Flags</code> 中，删除 <code>-lCrashReporterClient</code></p></li><li><p><code>Library not found for -loah</code><br>进入 <code>Targets -> objc -> Build Setting -> Other Linker Flags</code> 中，删除 <code>-loah</code></p></li></ul><h1 id="终于-Build-Succeded"><a href="#终于-Build-Succeded" class="headerlink" title="终于 Build Succeded"></a>终于 <code>Build Succeded</code></h1><img src="/2022/05/08/e233db870454/16520238050066.jpg" class=""><h1 id="添加测试-Target"><a href="#添加测试-Target" class="headerlink" title="添加测试 Target"></a>添加测试 <code>Target</code></h1><ol><li><p>新增Target<br>点击在 <code>Target</code> 左下角的 <code>+</code>, 然后选择 <code>macOS -> Command Line Tool</code>, 随便取名, 比如<code>TestOC</code></p><img src="/2022/05/08/e233db870454/16520245571391.jpg" class=""></li><li><p>链接<code>libobjc.A.dylib</code><br>选择 <code>Target -> TestOC -> General -> Frameworks and Libraries</code> 的 <code>+</code> 然后选择 <code>libobjc.A.dylib</code> 点击 <code>Add</code></p><img src="/2022/05/08/e233db870454/16520245370237.jpg" class=""></li></ol><h1 id="编译-TestOC-Target"><a href="#编译-TestOC-Target" class="headerlink" title="编译 TestOC Target"></a>编译 TestOC Target</h1><ol><li><p>选择新 Target - TestOC</p><img src="/2022/05/08/e233db870454/16520247646137.jpg" class=""></li><li><p>愉快的在main中写代码吧</p><img src="/2022/05/08/e233db870454/16520250796382.jpg" class=""></li><li><p>此时可能会发现, 断点发虚, 无法触发</p><img src="/2022/05/08/e233db870454/16520252735294.jpg" class=""><p> 断点失败, 解决方法有二</p><ul><li>第一种: 关闭LTO(<code>Link-Time Optimization</code>),<br> 找到<code>Targets -> Build Settings -> Link-Time Optimization</code>, 选择值为 <code>NO</code> 即可<br> LTO 代码链接时候的一个优化选项, Apple官方解释: <figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">Enabling this setting allows optimization across file boundaries during linking. </span><br><span class="line">**No:* </span><br><span class="line">Disabled. Do not use link-time optimization. </span><br><span class="line">**Monolithic Link-Time Optimization:*</span><br><span class="line">This mode performs monolithic link-time optimization of binaries, combining all executable code into a single unit and running aggressive compiler optimizations.</span><br><span class="line">**Incremental Link-Time Optimization:* </span><br><span class="line">This mode performs partitioned link-time optimization of binaries, inlining between compilation units and running aggressive compiler optimizations on each unit in parallel. This enables fast incremental builds and uses less memory than Monolithic LTO.</span><br></pre></td></tr></table></figure></li><li>第二种:<ol><li>找到 <code>Build Phases -> Compile Sources</code> 中，确保 <code>main.m</code> 在最最最前面</li><li>找到 <code>Targets -> Build Settings -> Enable Hardened Runtime</code> ，确保值为 <code>NO</code></li></ol></li></ul></li></ol>]]></content>
<tags>
<tag> Xcode </tag>
<tag> iOS </tag>
<tag> objc </tag>
</tags>
</entry>
<entry>
<title>macOS 使用SFMono字体</title>
<link href="/2019/08/29/3504b9da5c42.html"/>
<url>/2019/08/29/3504b9da5c42.html</url>
<content type="html"><![CDATA[<h3 id="从-macOS-中提取-SF-Mono-字体"><a href="#从-macOS-中提取-SF-Mono-字体" class="headerlink" title="从 macOS 中提取 SF Mono 字体"></a>从 macOS 中提取 SF Mono 字体</h3><h6 id="在-终端-中提取-SF-Mono-字体完整路径为："><a href="#在-终端-中提取-SF-Mono-字体完整路径为：" class="headerlink" title="在 终端 中提取 SF Mono 字体完整路径为："></a>在 终端 中提取 SF Mono 字体完整路径为：</h6><p><code>/Applications/Utilities/Terminal.app/Contents/Resources/Fonts/</code></p><h6 id="在-Xcode-中提取-SF-Mono-字体完整路径为："><a href="#在-Xcode-中提取-SF-Mono-字体完整路径为：" class="headerlink" title="在 Xcode 中提取 SF Mono 字体完整路径为："></a>在 Xcode 中提取 SF Mono 字体完整路径为：</h6><p><code>/Applications/Xcode.app/Contents/SharedFrameworks/DVTKit.framework/Versions/A/Resources/Fonts</code></p><span id="more"></span><h3 id="安装到系统。"><a href="#安装到系统。" class="headerlink" title="安装到系统。"></a>安装到系统。</h3><h6 id="通过-访达-安装"><a href="#通过-访达-安装" class="headerlink" title="通过 访达 安装"></a>通过 访达 安装</h6><p>在访达中通过路径前往文件夹鼠标操作：<code>菜单栏-->前往-->前往文件夹</code>；快捷键操作：<code>⇧+⌘+G</code>。然后输入上面的路径前往，然后全选所有字体文件，双击安装。</p><h6 id="通过-终端-命令行安装"><a href="#通过-终端-命令行安装" class="headerlink" title="通过 终端 命令行安装"></a>通过 终端 命令行安装</h6><p>打开终端，在终端输入此命令<br><code>cp -R /Applications/Utilities/Terminal.app/Contents/Resources/Fonts/*.otf ~/Library/Fonts/</code><br>回车即可</p>]]></content>
<tags>
<tag> macOS </tag>
<tag> mac </tag>
<tag> 字体 </tag>
</tags>
</entry>
<entry>
<title>go go go 2019</title>
<link href="/2019/08/28/6aaf43c133c4.html"/>
<url>/2019/08/28/6aaf43c133c4.html</url>
<content type="html"><![CDATA[<pre><code>有点生疏了</code></pre>]]></content>
</entry>
<entry>
<title>判断字符是否是纯数字</title>
<link href="/2016/11/24/e13e51eae9f1.html"/>
<url>/2016/11/24/e13e51eae9f1.html</url>
<content type="html"><![CDATA[<figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//使用NSScanner类， </span></span><br><span class="line">[<span class="keyword">self</span> isPureInt:text] <span class="comment">//传入字符串并调用方法判断</span></span><br><span class="line"></span><br><span class="line">- (<span class="type">BOOL</span>)isPureInt:(<span class="built_in">NSString</span>*)string{</span><br><span class="line"> <span class="built_in">NSScanner</span>* scan = [<span class="built_in">NSScanner</span> scannerWithString:string]; <span class="comment">//定义一个NSScanner，扫描string</span></span><br><span class="line"> <span class="type">int</span> val;</span><br><span class="line"> <span class="keyword">return</span> [scan scanInt:&val] && [scan isAtEnd];</span><br><span class="line">}</span><br></pre></td></tr></table></figure><span id="more"></span><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 同理 可以检测float double 等等格式</span></span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">//[scan scanInt:&val] </span></span><br><span class="line"><span class="comment">//扫描的Int类型放入val</span></span><br><span class="line"><span class="comment">//根据NSScanner的机制，如果扫描到结果需要的数据，那么它就会停在数据结尾的下一个字符处</span></span><br><span class="line"><span class="comment">//例如：string = @"12ccf12";如果扫描Int类型，那么第一次扫描到第二个字符处就停止了，如果要扫描全部需要进行循环判断</span></span><br><span class="line"><span class="comment">//扫描结束后，没有到string的结尾，那么[scan isAtEnd]为NO</span></span><br><span class="line"><span class="comment">//所以</span></span><br><span class="line"><span class="comment">//[scan isAtEnd] </span></span><br><span class="line"> <span class="comment">//判断是否到结尾</span></span><br><span class="line"><span class="comment">//这样就能保证一遍扫描到结尾的数据全部是int,[scan scanInt:&val] 和[scan isAtEnd]都为YES；</span></span><br><span class="line"><span class="comment">//结果isPureInt 返回YES；</span></span><br><span class="line"><span class="comment">//类似其他的判断也可以参考NSScanner</span></span><br><span class="line"></span><br></pre></td></tr></table></figure>]]></content>
<tags>
<tag> iOS </tag>
</tags>
</entry>
<entry>
<title>15分钟快速学会git</title>
<link href="/2016/09/24/c859e4c3dee5.html"/>
<url>/2016/09/24/c859e4c3dee5.html</url>
<content type="html"><![CDATA[<ol start="0"><li><p>初始化仓库<br> <strong>git init</strong> : 初始化仓库</p></li><li><p>检查状态<br> <strong>git status</strong> : 查看git状态</p></li><li><p>添加文件到缓存区<br> <strong>git add .</strong> : 把文件添加到缓存区</p></li><li><p>Committing<br> <strong>git commit -m “Add file”</strong> : 提交到缓存区</p><span id="more"></span></li><li><p>History<br> <strong>git log</strong> : 查看历史</p></li><li><p>远程存储库<br> <strong>git remote add origin <git库地址></strong> : 添加到远端git库</p></li><li><p>Pushing Remotely<br> <strong>git push -u origin master</strong> : 把master分支推到远端服务器</p></li><li><p>Pulling Remotely<br><strong>git pull origin master</strong> : 从远端服务器master分支拉取</p></li><li><p>Differences 比较提交<br><strong>git diff HEAD</strong> : 比较工作目录与上次提交时之间的所有差别</p></li><li><p>Staged Differences<br><strong>git diff –staged</strong> </p></li><li><p>Resetting the Stage<br><strong>git reset <file octofamily/octodog.txt></strong></p></li><li><p>Undo 撤销<br><strong>git checkout – <file></strong> : 撤销文件自从上次提交的所有更改</p></li><li><p>Branching Out 分支<br><strong>git branch clean_up</strong> : 创建名为clean_up的分支</p></li><li><p>Switching Branch 切换分支<br><strong>git checkout clean_up</strong> : 切换到clean_up分支</p></li><li><p>Removing All The Things 删除所有文件<br><strong>git rm ‘<file name>‘</strong> : 删除文件 (有个单引号)</p></li><li><p>Committing Branch Changes 提交分支中的变换<br><strong>git commit -m “Remove all the cats”</strong> : commit</p></li><li><p>Switching Branch 切回 主分支<br><strong>git checkout master</strong> : 回到master主分支</p></li><li><p>Preparing to Merge<br><strong>git merge clean_up</strong> : 当前在master主分支下操作, 把clean_up分支合并到master主分支</p></li><li><p>Delete Branch 为了保持工作区干净 删除用完的分支</p><p><strong>git branch -d clean_up</strong> 删除本地分支 <strong>-D</strong> 是强制删除<br>删除远端 多个push<br><strong>git push origin :serverfix</strong> : <strong>冒号写法</strong> 冒号前面空格不能少, 原理是把一个空分支push到server上，相当于删除该分支<br><strong>git push origin –delete serverfix</strong> –delete写法</p></li><li><p>The Final Push 最后一步 push<br><strong>git push</strong> : 推送到远端服务器</p></li></ol>]]></content>
<tags>
<tag> git </tag>
</tags>
</entry>
<entry>
<title>隐藏navigationBar底部的黑线shadowImage</title>
<link href="/2016/09/23/9adbb56f98f1.html"/>
<url>/2016/09/23/9adbb56f98f1.html</url>
<content type="html"><![CDATA[<ol><li><p>直接设置navigationBar的shadowImage和backgroundImage, 需先让translucent属性设置为NO</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">-(<span class="type">void</span>)removeBlackLine {</span><br><span class="line"> [<span class="keyword">self</span>.navigationController.navigationBar setBackgroundImage:[<span class="built_in">UIImage</span> new] forBarPosition:<span class="built_in">UIBarPositionAny</span> barMetrics:<span class="built_in">UIBarMetricsDefault</span>]; </span><br><span class="line"> [<span class="keyword">self</span>.navigationController.navigationBar setShadowImage:[<span class="built_in">UIImage</span> new]]; </span><br><span class="line">}</span><br></pre></td></tr></table></figure></li><li><p>循环遍历navigationBar的子视图，找到高度小于1的黑线, 在appear是隐藏, disappear时再显示（推荐）<span id="more"></span></p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="class"><span class="keyword">@implementation</span> <span class="title">ViewController</span> </span>{</span><br><span class="line"> <span class="built_in">UIImageView</span> *navBarHairlineImageView;</span><br><span class="line">}</span><br><span class="line">- (<span class="type">void</span>)viewWillAppear:(<span class="type">BOOL</span>)animated {</span><br><span class="line">[<span class="variable language_">super</span> viewWillAppear:animated];</span><br><span class="line"> navBarHairlineImageView.hidden = <span class="literal">YES</span>;</span><br><span class="line">}</span><br><span class="line">- (<span class="type">void</span>)viewWillDisappear:(<span class="type">BOOL</span>)animated {</span><br><span class="line">[<span class="variable language_">super</span> viewWillDisappear:animated];</span><br><span class="line"> navBarHairlineImageView.hidden = <span class="literal">NO</span>;</span><br><span class="line">} </span><br><span class="line">- (<span class="type">void</span>)viewDidLoad {</span><br><span class="line"> [<span class="variable language_">super</span> viewDidLoad];</span><br><span class="line"> navBarHairlineImageView= [<span class="keyword">self</span> findHairlineImageViewUnder:<span class="keyword">self</span>.navigationController.navigationBar];</span><br><span class="line"> <span class="comment">// Do any additional setup after loading the view, typically from a nib.</span></span><br><span class="line">}</span><br><span class="line">- (<span class="built_in">UIImageView</span> *)findHairlineImageViewUnder:(<span class="built_in">UIView</span> *)view { </span><br><span class="line"> <span class="keyword">if</span> ([view isKindOfClass:<span class="built_in">UIImageView</span>.class] && view.bounds.size.height <= <span class="number">1.0</span>) { </span><br><span class="line"> <span class="keyword">return</span> (<span class="built_in">UIImageView</span> *)view; </span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">for</span> (<span class="built_in">UIView</span> *subview <span class="keyword">in</span> view.subviews) { </span><br><span class="line"> <span class="built_in">UIImageView</span> *imageView = [<span class="keyword">self</span> findHairlineImageViewUnder:subview]; </span><br><span class="line"> <span class="keyword">if</span> (imageView) { </span><br><span class="line"> <span class="keyword">return</span> imageView; </span><br><span class="line"> } </span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">return</span> <span class="literal">nil</span>; </span><br><span class="line">} </span><br></pre></td></tr></table></figure></li><li><p>切去超出部分, 此方法会把状态栏给切掉</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">-(<span class="type">void</span>)useClipsToBoundsRemoveBlackLine { <span class="keyword">self</span>.navigationController.navigationBar.clipsToBounds = <span class="literal">YES</span>; </span><br><span class="line">} </span><br></pre></td></tr></table></figure></li></ol>]]></content>
<tags>
<tag> iOS </tag>
</tags>
</entry>
<entry>
<title>更改rootViewController时添加动画</title>
<link href="/2016/09/20/01edb6427252.html"/>
<url>/2016/09/20/01edb6427252.html</url>
<content type="html"><![CDATA[<p>当需要更换Window的rootViewController时，怎么给这个过程添加动画呢？</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">[<span class="built_in">UIView</span> transitionWithView:[[<span class="built_in">UIApplication</span> sharedApplication].delegate window]</span><br><span class="line"> duration:<span class="number">0.3</span></span><br><span class="line"> options:<span class="built_in">UIViewAnimationOptionTransitionCrossDissolve</span></span><br><span class="line"> animations:^{</span><br><span class="line"> [[[<span class="built_in">UIApplication</span> sharedApplication].delegate window] setRootViewController:viewController];</span><br><span class="line"> }</span><br><span class="line"> completion:<span class="literal">NULL</span>];</span><br></pre></td></tr></table></figure><p>这样写咋看咋对, 试试也是对的, <span id="more"></span> 但当横屏时会发现动画很奇怪, 后来在stackoverflow看到一个解决办法</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">[<span class="built_in">UIView</span> transitionWithView:[[<span class="built_in">UIApplication</span> sharedApplication].delegate window]</span><br><span class="line"> duration:<span class="number">0.3</span></span><br><span class="line"> options:<span class="built_in">UIViewAnimationOptionTransitionCrossDissolve</span></span><br><span class="line"> animations:^{</span><br><span class="line"> <span class="type">BOOL</span> oldState = [<span class="built_in">UIView</span> areAnimationsEnabled];</span><br><span class="line"> [<span class="built_in">UIView</span> setAnimationsEnabled:<span class="literal">NO</span>];</span><br><span class="line"> [[[<span class="built_in">UIApplication</span> sharedApplication].delegate window] setRootViewController:viewController];</span><br><span class="line"> [<span class="built_in">UIView</span> setAnimationsEnabled:oldState];</span><br><span class="line"> }</span><br><span class="line"> completion:<span class="literal">NULL</span>];</span><br></pre></td></tr></table></figure>]]></content>
<tags>
<tag> iOS </tag>
</tags>
</entry>
<entry>
<title>AlertController的Click方法封装</title>
<link href="/2016/08/31/6f517186ba1f.html"/>
<url>/2016/08/31/6f517186ba1f.html</url>
<content type="html"><![CDATA[<p>封装的AlertController, 不至于每次写alert时 好多Block回调;<br>先上 <a href="https://github.com/ijunfly/JFAlertViewController">JFAlertViewController</a>地址 <a href="https://github.com/ijunfly/JFAlertViewController">https://github.com/ijunfly/JFAlertViewController</a></p><p>每次写AlertView时每个按钮都要写一个Block来回调方法, 这样会使代码太多</p><p>创建一个继承于JFAlertViewController的属性对象</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">@property</span> (<span class="keyword">strong</span>, <span class="keyword">nonatomic</span>) JFAlertViewController *alertAllVC;</span><br></pre></td></tr></table></figure><p>初始化时要遵循delegate和dataSource</p><span id="more"></span><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">pragma</span> mark - getting</span></span><br><span class="line">- (JFAlertViewController *)alertAllVC {</span><br><span class="line"> <span class="keyword">if</span> (!_alertAllVC) {</span><br><span class="line"> _alertAllVC = [JFAlertViewController alertControllerWithTitle:<span class="string">@"我是标题"</span> message:<span class="string">@"我是消息, 消息内容的消息..."</span> preferredStyle:<span class="built_in">UIAlertControllerStyleAlert</span>];</span><br><span class="line"> _alertAllVC.delegate = <span class="keyword">self</span>;</span><br><span class="line"> _alertAllVC.dataSource = <span class="keyword">self</span>;</span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">return</span> _alertAllVC;</span><br><span class="line">}</span><br></pre></td></tr></table></figure><p>然后就可以写dataSource和delegate方法了</p><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">//返回选项的个数 (cancel按钮不计算在内)</span></span><br><span class="line">- (<span class="built_in">NSUInteger</span>)numberOfIndexsInJFAlertView:(JFAlertViewController *)alertView;</span><br><span class="line"><span class="comment">//返回选项的title</span></span><br><span class="line">- (<span class="built_in">NSString</span> *)JFAlertView:(JFAlertViewController *)alertView titleAtIndexNumber:(<span class="built_in">NSUInteger</span>)index;</span><br><span class="line"><span class="keyword">@optional</span></span><br><span class="line"><span class="comment">//返回cancel按钮title, 默认是:"取消"</span></span><br><span class="line">- (<span class="built_in">NSString</span> *)cancelButtonTitleInJFAlertView:(JFAlertViewController *)alertView;</span><br></pre></td></tr></table></figure><figure class="highlight objectivec"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 选项的点击事件</span></span><br><span class="line">- (<span class="type">void</span>)JFAlertView:(JFAlertViewController *)alertView clickedAtIndex:(<span class="built_in">NSUInteger</span>)index;</span><br><span class="line"></span><br><span class="line"><span class="comment">//cancel按钮的点击事件</span></span><br><span class="line">- (<span class="type">void</span>)JFAlertViewCancel:(JFAlertViewController *)alertView;</span><br></pre></td></tr></table></figure><p>欢迎指正…</p><p>demo改天再传….</p>]]></content>
<tags>
<tag> iOS </tag>
</tags>
</entry>
<entry>
<title>放羊人与砍柴人的故事</title>
<link href="/2016/08/30/3023662f8e20.html"/>
<url>/2016/08/30/3023662f8e20.html</url>
<content type="html"><![CDATA[<p>你是砍柴的，他是放羊的，你和他聊了一天，他的羊吃饱了，你的柴呢？ 砍柴的陪不起放羊的——请放弃你的无效社交！</p><p>你是砍柴的，他是放羊的，你和他聊了一天，如是你学会了放羊技巧，<span id="more"></span>原来羊是这么放的，他学会了砍柴技能，原来柴要这样砍——三人行必有我师，永远保持空杯的状态！</p><p>你是砍柴的，他是放羊的，你和他聊了一天，他决定把他的羊跟你的柴交换，于是你有了羊，他也有了柴——等价交换，不要看不起任何人，天生我才必有用！</p><p>你是砍柴的，他是放羊的，你和他聊了一天，他把他买羊的客户介绍给了你，你把你买柴的客户介绍给了他，于是你们各自的生意越做越大——资源整合很重要！</p><p>你是砍柴的，他是放羊的，你和他聊了一天，你们决定合作一起开个烤全羊的店，你的柴烤出来的羊很美味，他的羊纯天然的，几年后你们公司上市了——没有完美的个人，只有完美的团队！<br>……</p><p>其实面对同一件事物 心态不一样 结果就会不一样！我想说，聊可以瞎聊，沟通却是有目的的。</p><img src="/2016/08/30/3023662f8e20/160830-fangyangren.jpg" class="">]]></content>
<tags>
<tag> 故事 </tag>
</tags>
</entry>
<entry>
<title>Xcode插件管理工具-Alcatraz</title>
<link href="/2016/08/26/7472c647ead7.html"/>
<url>/2016/08/26/7472c647ead7.html</url>
<content type="html"><![CDATA[<h1 id="Xcode插件"><a href="#Xcode插件" class="headerlink" title="Xcode插件"></a>Xcode插件</h1><p><strong>Alcatraz</strong>是管理Xcode插件的插件, 集成在Xcode图形界面中.<br><em>Xcode8中Apple禁止了Xcode安装插件</em></p><p>手动安装Alcatraz, 在GitHub主页上找搜索<a href="https://github.com/alcatraz/Alcatraz">Alcatrazde</a> , 或者浏览器地址栏直接输入<a href="https://github.com/alcatraz/Alcatraz">https://github.com/alcatraz/Alcatraz</a></p><img src="/2016/08/26/7472c647ead7/0826-1472176469450.png" class=""><ul><li><span id="more"></span>点击[Clone or download]选择 Download ZIP (如上图)，进行下载。</li></ul><p>下载完，解压ZIP, 双击打开 .xcodeproj 可执行文件，会打开Xcode，之后运行这个项目工程</p><img src="/2016/08/26/7472c647ead7/0826-1472176649167.png" class=""><p>运行完，会出现一个会话弹出框，不要慌，这不是出现什么错误了(其实我刚开始看见这个的时候慌了一下)，淡定的点击 Load Bundles</p><img src="/2016/08/26/7472c647ead7/0826-1472176707103.png" class=""><p>然后关闭Xcode(或者command ＋ Q), 重新打开Xcode<br>点击Windows可以看到Package Manager(Shift+Command+9)</p><img src="/2016/08/26/7472c647ead7/0826-1472176837716.png" class=""><p>此时就可以打开Alcatraz管理工具了</p><img src="/2016/08/26/7472c647ead7/0826-1472177132229.png" class=""><p><a href="http://www.cocoachina.com/ios/20160122/15080.html">Xcode 插件优缺点对比（推荐 20 款插件）</a></p><p><a href="http://www.tuicool.com/articles/zUZnAfj">工作中的常用插件 for Xcode</a></p>]]></content>
<tags>
<tag> Xcode </tag>
<tag> iOS </tag>
</tags>
</entry>
<entry>
<title>git基础命令</title>
<link href="/2016/08/25/64b2c31ab32a.html"/>
<url>/2016/08/25/64b2c31ab32a.html</url>
<content type="html"><![CDATA[<p><strong>pwd</strong> 命令用于显示当前目录</p><p><strong>git init</strong>命令把这个目录变成Git可以管理的仓库</p><p>现有的仓库 <strong>git remote add origin <a href="mailto:git@192.168.1.235">git@192.168.1.235</a>:iOSTeam/xxx.git</strong> 这个要替换项目地址</p><p><strong>ssh-add</strong> ~/.ssh/xxx_id_rsa 添加sshKey 不至于每次输入密码</p><p>用ls -ah命令就可以看见所有文件</p><p><strong>git add</strong> 文件名字.后缀 git add . // 所有文件</p><p><strong>git status</strong> 状态<br> <span id="more"></span><br><strong>git commit -m “xxx”</strong> 提交</p><p><strong>git log</strong> 命令查看<br>git log –pretty=oneline 参数 显示 commit id（版本号）</p><p><strong>git diff</strong> 查看修改内容</p><p><strong>git reset</strong> 命令 回退到上一个版本 git reset –hard HEAD^^^^ / HEAD~4<br>还有个方法只要上面的命令行窗口还没有被关掉，你就可以顺着往上找啊找啊，找到那个append GPL的commit id是3628164…，于是就可以指定回到未来的某个版本：<br>git reset –hard 3628164</p><p><strong>git reflog</strong> 用来记录你的每一次命令</p><p><strong>cat readme.txt</strong> 打开文件</p><p><strong>git checkout -</strong> <file> 可以丢弃工作区的修改 , 没有–，就变成了“切换到另一个分支”的命令，<br>git reset HEAD <file> 可以把暂存区的修改撤销掉（unstage），重新放回工作区：</p><p><strong>git rm</strong> 删掉，</p><hr><p><strong>git push origin master</strong> 推到远程master分支</p>]]></content>
<tags>
<tag> git </tag>
</tags>
</entry>
<entry>
<title>Hello World</title>
<link href="/2016/08/20/31047e7c1977.html"/>
<url>/2016/08/20/31047e7c1977.html</url>
<content type="html"><![CDATA[<p>Welcome to <a href="https://hexo.io/">Hexo</a>! This is your very first post. Check <a href="https://hexo.io/docs/">documentation</a> for more info. If you get any problems when using Hexo, you can find the answer in <a href="https://hexo.io/docs/troubleshooting.html">troubleshooting</a> or you can ask me on <a href="https://github.com/hexojs/hexo/issues">GitHub</a>.</p><h2 id="Quick-Start"><a href="#Quick-Start" class="headerlink" title="Quick Start"></a>Quick Start</h2><ul><li><span id="more"></span><h3 id="Create-a-new-post"><a href="#Create-a-new-post" class="headerlink" title="Create a new post"></a>Create a new post</h3></li></ul><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo new <span class="string">"My New Post"</span></span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/writing.html">Writing</a></p><h3 id="Run-server"><a href="#Run-server" class="headerlink" title="Run server"></a>Run server</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo server</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/server.html">Server</a></p><h3 id="Generate-static-files"><a href="#Generate-static-files" class="headerlink" title="Generate static files"></a>Generate static files</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo generate</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/generating.html">Generating</a></p><h3 id="Deploy-to-remote-sites"><a href="#Deploy-to-remote-sites" class="headerlink" title="Deploy to remote sites"></a>Deploy to remote sites</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo deploy</span><br></pre></td></tr></table></figure><p>More info: <a href="https://hexo.io/docs/deployment.html">Deployment</a></p>]]></content>
</entry>
<entry>
<title>新的开篇</title>
<link href="/2016/08/15/02fee1cc85dd.html"/>
<url>/2016/08/15/02fee1cc85dd.html</url>
<content type="html"><![CDATA[<h1 id="暂时的离别是为了再次相聚时的感动"><a href="#暂时的离别是为了再次相聚时的感动" class="headerlink" title="暂时的离别是为了再次相聚时的感动"></a>暂时的离别是为了再次相聚时的感动</h1><hr><h4 id="离别"><a href="#离别" class="headerlink" title="离别"></a>离别</h4><p>离别的时候<br>每一句话都是那么重<br>缓缓地扣击着我们的心灵<br>窗被敲开了<br>我们诉说着回忆中的快乐<br>回想著一张张可爱的笑脸<br>院子里，操场上<br>充满了甜甜的空气 </p><ul><li><span id="more"></span>离别的时候<br>每一句话都是那么轻<br>轻轻地说着离别时的感言<br>轻轻的拉着彼此的手<br>轻轻地在耳际说声对不起<br>或永远祝福你</li></ul><p>离别的时候<br>每一句话都显得那么悲伤<br>离别时的感动在顷刻间爆发<br>我们，我们，我们<br>独自沉浸在自己的感伤中<br>渐渐的平息…… </p><p>离别的时候<br>每一句话都显得那么珍贵<br>仔细的听著那熟悉的声音<br>把每种都印刻在记忆里 </p><p>望著他们远去的背影，我知道，我们离别了<br>我们带著共同的回忆和永远的祝福<br>各自奔向远方……<br>轻轻哼一首离别的歌～<br>眼里噙满了泪…… </p><h4 id="重逢"><a href="#重逢" class="headerlink" title="重逢"></a>重逢</h4><p>重逢的时候<br>那是心情的又一次触动<br>惊喜的表情<br>熟悉的面庞<br>回忆中的甜蜜<br>一瞬间在脑海中隐现<br>于是，永远成为了所谓的缘分的代表<br>重逢…惊喜…<br>重逢的时候<br>那是思念的又一次宣泄<br>深情的一个拥抱<br>紧紧的一个握手<br>彼此的心轻鬆了许多<br>才发现思念是一种病<br>重逢…思念……<br>重逢的时候<br>那是记忆的又一次翻新<br>彼此回忆著孩提时的美好<br>诉说着自己的苦恼<br>谈论着朋友的生活<br>讲述着自己无奈的过往<br>重逢…记忆…<br>重逢的时候<br>那是时间的又一次停滞<br>那一刻，时间终于停了<br>自己终于可以放假<br>感动的身体一时瘫在那里<br>重逢时的感动告诉了时光老人<br>时间不能改变的东西……<br>重逢…感动…<br>重逢的时候，那是一阵欣喜，一阵感动<br>欣喜之余还有一丝的忧伤<br>因为我们毕竟还要赶路<br>那么多线终有相交的一点<br>可是相交以后注定还要分别<br>但是，至少我明白<br>暂时的离别是为了再次相聚时的感动…… </p>]]></content>
<tags>
<tag> 杂谈 </tag>
</tags>
</entry>
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