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HTML5 canvas 参考手册.html
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<!DOCTYPE html>
<html>
<head>
<meta name="renderer" content="webkit">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta property="qc:admins" content="465267610762567726375">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>HTML5 画布 Canvs 参考手册</title>
<style>
*{border:0;margin:0;padding:0;}
body {
font-family: Helvetica Neue,Helvetica,PingFang SC,Hiragino Sans GB,Microsoft YaHei,Noto Sans CJK SC,WenQuanYi Micro Hei,Arial,sans-serif;
-webkit-font-smoothing: antialiased;
background: #f6f6f6;
color: #333;
}
hr {
background-color: #d4d4d4;
color: #d4d4d4;
height: 1px;
border: 0;
clear: both;
}
a {
color: #64854c;
text-decoration: none;
}
table a {
text-decoration: underline;
}
button, input, select, td, textarea, th {
font-size: 13px;
}
.article-body, .article-detail{
padding: 0px 0px 0px 10px;
width: 800px;
}
.article-body p {
font-size: 13px;
line-height: 2em;
}
.article-intro h1 {
margin: 0 0 10px 0;
font-size: 2.1em;
text-indent: initial;
text-decoration: none;
color: #000;
}
.article-intro h1 span {
color: #64854c;
}
.article-body h2 {
font-size: 1.2em;
margin: 2px 0;
line-height: 1.8em;
}
table.reference, table.tecspec {
border-collapse: collapse;
width: 100%;
margin-bottom: 4px;
margin-top: 4px;
}
table.reference th {
color: #fff;
background-color: #555;
border: 1px solid #555;
font-size: 12px;
padding: 3px;
vertical-align: top;
text-align: left;
}
table.reference tr:nth-child(odd) {
background-color: #f6f4f0;
}
table.reference tr:nth-child(even) {
background-color: #fff;
}
table.reference td {
line-height: 2em;
min-width: 24px;
border: 1px solid #d4d4d4;
padding: 5px;
padding-top: 7px;
padding-bottom: 7px;
vertical-align: top;
}
td ul{
margin-left: 30px;
}
h2 {
display: block;
font-size: 1.5em;
-webkit-margin-before: 0.83em;
-webkit-margin-after: 0.83em;
-webkit-margin-start: 0px;
-webkit-margin-end: 0px;
font-weight: bold;
}
div.example {
width: 98%;
color: #000;
background-color: #e5eecc;
margin: 0 0 5px 0;
padding: 5px;
border: 1px solid #d4d4d4;
background-image: -webkit-linear-gradient(#fff,#e5eecc 100px);
background-image: linear-gradient(#fff,#e5eecc 100px);
}
h2.example, h2.example_head {
color: #617f10;
margin-top: 0;
font-size: 13px;
}
div.tryit_ex {
clear: both;
width: 600px;
height: 50px;
margin-bottom: 5px;
}
div.tryit_ex h2 {
padding-top: 3px;
}
div.tryit_ex img {
border: 0;
float: left;
margin-right: 10px;
width: 40px;
height: 46px;
}
table.tecspec td, table.tecspec th {
border: 1px solid #d4d4d4;
padding: 5px;
padding-top: 7px;
padding-bottom: 7px;
vertical-align: top;
text-align: left;
}
canvas {
border: 1px solid #d3d3d3;
background: #ffffff;
}
div.example_code {
line-height: 1.4em;
width: 98%;
background-color: #fff;
padding: 5px;
border: 1px solid #d4d4d4;
font-size: 13px;
font-family: Menlo,Monaco,Consolas,"Andale Mono","lucida console","Courier New",monospace;
word-break: break-all;
word-wrap: break-word;
}
a.showbtn, a.showbtn:link, a.showbtn:visited, a.tryitbtn, a.tryitbtn:link, a.tryitbtn:visited {
display: inline-block;
color: #FFF;
background-color: #8ac007;
font-weight: 700;
font-size: 12px;
text-align: center;
padding-left: 10px;
padding-right: 10px;
padding-top: 3px;
padding-bottom: 4px;
text-decoration: none;
margin-left: 5px;
margin-top: 0;
margin-bottom: 5px;
border: 1px solid #aaa;
border-radius: 5px;
white-space: nowrap;
}
#catalog_min{
position: fixed;
top: 0;
right: 20px;
cursor:pointer;
height: 100%;
overflow: auto;
}
#catalog_min ul{
overflow:auto;
display: table-cell;
}
#catalog_min ul li.attrb{
color: #fb00ff;
}
#catalog_min ul li.func{
color: blue;
}
#DetailContent{
position: fixed;
top: 0;
left: 0;
background-color: #fff;
height: 100%;
width: 100%;
overflow: auto;
}
.article-detail{
display: none;
position: absolute;
top: 0;
left: 0;
}
#closeBtn{
right: 19px;
top: 3px;
color: white;
position: fixed;
background: red;
cursor: pointer;
padding: 3px 8px;
}
pre{
background-color: #fff;
border: 1px solid #d4d4d4;
padding: 3px;
}
</style>
<script>
function G(id){return document.getElementById(id);}
</script>
</head>
<body>
<div id="Catalog" class="article-body">
<div class="article-intro" id="content">
<h1>HTML5 <span class="color_h1"><canvas></span> 参考手册</h1><hr>
<h2 id="catalog__">描述</h2>
<p>HTML5 <canvas> 标签用于绘制图像（通过脚本，通常是 JavaScript）。</p>
<p>不过，<canvas> 元素本身并没有绘制能力（它仅仅是图形的容器） - 您必须使用脚本来完成实际的绘图任务。</p>
<p>getContext() 方法可返回一个对象，该对象提供了用于在画布上绘图的方法和属性。</p>
<p>本手册提供大部分的 getContext("2d") 对象的属性和方法，可用于在画布上绘制文本、线条、矩形、圆形等等。</p>
<hr>
完整手册在<b><a href="https://developer.mozilla.org/zh-CN/docs/Web/API/CanvasRenderingContext2D">这里</a></b>有
<hr>
<h2>浏览器支持</h2>
<p>
<img src="http://www.runoob.com/images/compatible_ie.gif" width="31" height="30" alt="Internet Explorer" title="Internet Explorer">
<img src="http://www.runoob.com/images/compatible_firefox.gif" width="31" height="30" alt="Firefox" title="Firefox">
<img src="http://www.runoob.com/images/compatible_opera.gif" width="28" height="30" alt="Opera" title="Opera">
<img src="http://www.runoob.com/images/compatible_chrome.gif" width="31" height="30" alt="Google Chrome" title="Google Chrome">
<img src="http://www.runoob.com/images/compatible_safari.gif" width="28" height="30" alt="Safari" title="Safari">
</p>
<p>Internet Explorer 9、Firefox、Opera、Chrome 和 Safari 支持 <canvas> 标签的属性及方法。</p>
<p><b>注意:</b>Internet Explorer 8 及更早的IE版本不支持 <canvas> 元素。</p>
<hr>
<h2 id="catalog_0">canvas 状态</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_canvas">canvas</td>
<td>对 HTMLCanvasElement 只读的反向引用。如果和 <canvas> 元素没有联系，可能为null。</td>
</tr>
</table>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_save"><a href="canvas-save-restore.html">save()</a></td>
<td>保存当前环境的状态和属性，到状态栈。状态和属性包含:strokeStyle, fillStyle, globalAlpha, lineWidth, lineCap, lineJoin, miterLimit, shadowOffsetX, shadowOffsetY, shadowBlur, shadowColor, globalCompositeOperation 的值</td>
</tr>
<tr>
<td id="fun_restore"><a href="canvas-save-restore.html">restore()</a></td>
<td>从状态栈， 返回之前保存过的路径状态和属性。状态和属性的包含和save()一样</td>
</tr>
<tr>
<td id="fun_getcontext">getContext(type)</td>
<td>获取上下文对象(CanvasRenderingContext2D)，例： getContext('2d')</td>
</tr>
</table>
<h2 id="catalog_1">样式、渐变和阴影</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_fillstyle"><a href="canvas-fillstyle.html">fillStyle</a></td>
<td>设置或返回用于填充绘画的颜色、渐变或模式。</td>
</tr>
<tr>
<td id="attr_strokestyle"><a href="canvas-strokestyle.html">strokeStyle</a></td>
<td>设置或返回用于笔触的颜色、渐变或模式。</td>
</tr>
<tr>
<td id="attr_shadowcolor"><a href="canvas-shadowcolor.html">shadowColor</a></td>
<td>设置或返回用于阴影的颜色。</td>
</tr>
<tr>
<td id="attr_shadowblur"><a href="canvas-shadowblur.html">shadowBlur</a></td>
<td>设置或返回用于阴影的模糊级别。</td>
</tr>
<tr>
<td id="attr_shadowoffsetx"><a href="canvas-shadowoffsetx.html">shadowOffsetX</a></td>
<td>设置或返回阴影与形状的水平距离。</td>
</tr>
<tr>
<td id="attr_shadowoffsety"><a href="canvas-shadowoffsety.html">shadowOffsetY</a></td>
<td>设置或返回阴影与形状的垂直距离。</td>
</tr>
</table>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_createlineargradient"><a href="canvas-createlineargradient.html">createLinearGradient(x0,y0,x1,y1);</a></td>
<td>创建线性渐变（用在画布内容上）。</td>
</tr>
<tr>
<td id="fun_createpattern"><a href="canvas-createpattern.html">createPattern(image,repeatStyle)</a></td>
<td>在指定的方向上重复指定的元素。</td>
</tr>
<tr>
<td id="fun_createradialgradient"><a href="canvas-createradialgradient.html">createRadialGradient(x0,y0,r0,x1,y1,r1)</a></td>
<td>创建放射状/环形的渐变（用在画布内容上）。</td>
</tr>
<tr>
<td id="fun_addcolorstop"><a href="canvas-addcolorstop.html">addColorStop(stop,color)</a></td>
<td>规定渐变对象中的颜色和停止位置。</td>
</tr>
</table>
<h2 id="catalog_2">线条、虚线样式</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_linecap"><a href="canvas-linecap.html">lineCap</a></td>
<td>设置或返回线条的结束端点样式。</td>
</tr>
<tr>
<td id="attr_linejoin"><a href="canvas-linejoin.html">lineJoin</a></td>
<td>设置或返回两条线相交时，所创建的拐角类型。</td>
</tr>
<tr>
<td id="attr_linewidth"><a href="canvas-linewidth.html">lineWidth</a></td>
<td>设置或返回当前的线条宽度。</td>
</tr>
<tr>
<td id="attr_miterlimit"><a href="canvas-miterlimit.html">miterLimit</a></td>
<td>设置或返回最大斜接长度。</td>
</tr>
<tr>
<td id="attr_lineDashOffset"><a href="canvas-lineDashOffset.html">lineDashOffset</a></td>
<td>设置虚线样式的起始偏移量。</td>
</tr>
</table>
<br/>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_getlinedash"><a href="canvas-getlinedash.html">getLineDash()</a></td>
<td>返回一个包含当前虚线样式，长度为非负偶数的数组。 如：[5,3]</td>
</tr>
<tr>
<td id="fun_setlinedash"><a href="canvas-setlinedash.html">setLineDash(segments)</a></td>
<td>设置当前虚线样式。如：setLineDash([5, 3])</td>
</tr>
</table>
<h2 id="catalog_3">矩形</h2>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_rect"><a href="canvas-rect.html">rect(x,y,width,height)</a></td>
<td>创建矩形。</td>
</tr>
<tr>
<td id="fun_fillrect"><a href="canvas-fillrect.html">fillRect(x,y,width,height)</a></td>
<td>绘制"被填充"的矩形。</td>
</tr>
<tr>
<td id="fun_strokerect"><a href="canvas-strokerect.html">strokeRect(x,y,width,height)</a></td>
<td>绘制矩形（无填充）。</td>
</tr>
<tr>
<td id="fun_clearrect"><a href="canvas-clearrect.html">clearRect(x,y,width,height)</a></td>
<td>在给定的矩形内清除指定的像素。</td>
</tr>
</table>
<h2 id="catalog_4">路径</h2>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_fill"><a href="canvas-fill.html">fill()</a></td>
<td>填充当前绘图（路径）。</td>
</tr>
<tr>
<td id="fun_stroke"><a href="canvas-stroke.html">stroke()</a></td>
<td>绘制已定义的路径。</td>
</tr>
<tr>
<td id="fun_beginpath"><a href="canvas-beginpath.html">beginPath()</a></td>
<td>起始一条路径，或重置当前路径。</td>
</tr>
<tr>
<td id="fun_closepath"><a href="canvas-closepath.html">closePath()</a></td>
<td>创建从当前点回到起始点的路径。</td>
</tr>
<tr>
<td id="fun_moveto"><a href="canvas-moveto.html">moveTo(x,y)</a></td>
<td>把路径移动到画布中的指定点，不创建线条。</td>
</tr>
<tr>
<td id="fun_lineto"><a href="canvas-lineto.html">lineTo(x,y)</a></td>
<td>添加一个新点，然后在画布中创建从该点到最后指定点的线条。</td>
</tr>
<tr>
<td id="fun_clip"><a href="canvas-clip.html">clip()</a></td>
<td>从原始画布剪切任意形状和尺寸的区域。</td>
</tr>
<tr>
<td id="fun_quadraticcurveto"><a href="canvas-quadraticcurveto.html">quadraticCurveTo(cpx,cpy,x,y);</a></td>
<td>创建二次贝塞尔曲线。</td>
</tr>
<tr>
<td id="fun_beziercurveto"><a href="canvas-beziercurveto.html">bezierCurveTo(cp1x,cp1y,cp2x,cp2y,x,y)</a></td>
<td>创建三次贝塞尔曲线。</td>
</tr>
<tr>
<td id="fun_arc"><a href="canvas-arc.html">arc(x,y,r,startAngle,endAngle,anticlockwise)</a></td>
<td>绘制一段圆弧路径（用于创建圆形或部分圆）。</td>
</tr>
<tr>
<td id="fun_arcto"><a href="canvas-arcto.html">arcTo(x1,y1,x2,y2,r)</a></td>
<td>创建两切线之间的弧/曲线。</td>
</tr>
<tr>
<td id="fun_ellipse"><a href="canvas-ellipse.html">ellipse(x,y,radiusX,radiusY,rotation,startAngle,endAngle,anticlockwise)</a></td>
<td>绘制一个椭圆路径（用于创建椭圆或部分椭圆）。</td>
</tr>
<tr>
<td id="fun_ispointinpath"><a href="canvas-ispointinpath.html">isPointInPath(x,y)</a></td>
<td>如果指定的点位于当前路径中，则返回 true，否则返回 false。</td>
</tr>
</table>
<h2 id="catalog_5">变换</h2>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_scale"><a href="canvas-scale.html">scale(scalewidth,scaleheight)</a></td>
<td>缩放当前绘图至更大或更小。</td>
</tr>
<tr>
<td id="fun_rotate"><a href="canvas-rotate.html">rotate(angle)</a></td>
<td>旋转当前绘图。旋转圆心为(0,0)点。</td>
</tr>
<tr>
<td id="fun_translate"><a href="canvas-translate.html">translate(x,y)</a></td>
<td>重新映射画布上的 (0,0) 位置。</td>
</tr>
<tr>
<td id="fun_transform"><a href="canvas-transform.html">transform(a,b,c,d,e,f)</a></td>
<td>替换绘图的当前转换矩阵。</td>
</tr>
<tr>
<td id="fun_settransform"><a href="canvas-settransform.html">setTransform(a,b,c,d,e,f)</a></td>
<td>重新设置当前的变换为单位矩阵，并使用同样的变量调用 transform() 方法。</td>
</tr>
<tr>
<td id="fun_resettransform"><a href="canvas-resettransform.html">resetTransform(a,b,c,d,e,f)</a></td>
<td>使用单位矩阵重新设置当前的变换。</td>
</tr>
</table>
<h2 id="catalog_6">文本</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_font"><a href="canvas-font.html">font</a></td>
<td>设置或返回文本内容的当前字体属性。</td>
</tr>
<tr>
<td id="attr_textalign"><a href="canvas-textalign.html">textAlign</a></td>
<td>设置或返回文本内容的当前对齐方式。</td>
</tr>
<tr>
<td id="attr_textbaseline"><a href="canvas-textbaseline.html">textBaseline</a></td>
<td>设置或返回在绘制文本时使用的当前文本基线。</td>
</tr>
</table>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_filltext"><a href="canvas-filltext.html">fillText(text,x,y,maxWidth)</a></td>
<td>在画布上绘制"被填充的"文本。</td>
</tr>
<tr>
<td id="fun_stroketext"><a href="canvas-stroketext.html">strokeText(text,x,y,maxWidth)</a></td>
<td>在画布上绘制文本（无填充,空心）。</td>
</tr>
<tr>
<td id="fun_measuretext"><a href="canvas-measuretext.html">measureText(text)</a></td>
<td>返回包含指定文本宽度的<u>对象</u>。</td>
</tr>
</table>
<h2 id="catalog_7">图像绘制</h2>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_drawimage"><a href="canvas-drawimage.html">drawImage(img,sx,sy,swidth,sheight,x,y,width,height)</a></td>
<td>向画布上绘制图像、画布或视频。可进行定位、裁剪。</td>
</tr>
</table>
<h2 id="catalog_8">像素操作</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_width"><a href="canvas-width.html">width</a></td>
<td>返回 ImageData 对象的宽度。</td>
</tr>
<tr>
<td id="attr_height"><a href="canvas-height.html">height</a></td>
<td>返回 ImageData 对象的高度。</td>
</tr>
<tr>
<td id="attr_data"><a href="canvas-data.html">data</a></td>
<td>返回一个对象，其包含指定的 ImageData 对象的图像数据。</td>
</tr>
</table>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_createimagedata"><a href="canvas-createimagedata.html">createImageData([width,height]|[imageData])</a></td>
<td>创建新的、空白的 ImageData 对象。</td>
</tr>
<tr>
<td id="fun_getimagedata"><a href="canvas-getimagedata.html">getImageData(x,y,width,height)</a></td>
<td>返回 ImageData 对象，该对象为画布上指定的矩形复制像素数据。</td>
</tr>
<tr>
<td id="fun_putimagedata"><a href="canvas-putimagedata.html">putImageData(imgData,x,y,dirtyX,dirtyY,dirtyWidth,dirtyHeight)</a></td>
<td>把图像数据（从指定的 ImageData 对象）放回画布上。</td>
</tr>
</table>
<h2 id="catalog_9">合成</h2>
<table class="reference">
<tr>
<th align="left" width="25%">属性</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="attr_globalalpha"><a href="canvas-globalalpha.html">globalAlpha</a></td>
<td>设置或返回绘图的当前(全局) alpha 或透明值。</td>
</tr>
<tr>
<td id="attr_globalcompositeoperation"><a href="canvas-globalcompositeoperation.html">globalCompositeOperation</a></td>
<td>设置或返回使用何种合成或混合模式，将新图像绘制到已有的图像上。</td>
</tr>
</table>
<h2 id="catalog_10">点击区域</h2>
<table class="reference">
<tr>
<th align="left" width="25%">方法</th>
<th align="left" width="75%">描述</th>
</tr>
<tr>
<td id="fun_addhitregion"><a href="canvas-addhitregion.html">addHitRegion() </a></td>
<td>在canvas上添加一个点击区域。<i>(实验功能)</i></td>
</tr>
<tr>
<td id="fun_removehitregion"><a href="canvas-removehitregion.html">removeHitRegion(id) </a></td>
<td>从canvas上移除指定id的点击区域。<i>(实验功能)</i></td>
</tr>
<tr>
<td id="fun_clearhitregions"><a href="canvas-clearhitregions.html">clearHitRegions() </a></td>
<td>移除canvas上的所有点击区域。<i>(实验功能)</i></td>
</tr>
</table>
</div>
<div id="ext_func">
<h2>扩展函数</h2>
<pre>
Object.assign(CanvasRenderingContext2D.prototype,{
//圆角矩形
strokeRect(x,y,width,height,radius){ //圆角矩形
radius=Math.abs(radius||0);
this.beginPath();
this.moveTo(x,y+radius);
this.lineTo(x,y+height-radius);
this.quadraticCurveTo(x,y+height,x+radius,y+height);
this.lineTo(x+width-radius,y+height);
this.quadraticCurveTo(x+width,y+height,x+width,y+height-radius);
this.lineTo(x+width,y+radius);
this.quadraticCurveTo(x+width,y,x+width-radius,y);
this.lineTo(x+radius,y);
this.quadraticCurveTo(x,y,x,y+radius);
this.stroke();
},
//圆圈
strokeCircle(x,y,r){ //圆圈
this.beginPath();
this.arc(x,y,r,0,2*Math.PI);
this.stroke();
},
fillCircle(x,y,r){
this.beginPath();
this.arc(x,y,r,0,2*Math.PI);
this.fill();
},
//画线
line(x1,y1,x2,y2){ //画线
this.beginPath();
this.moveTo(x1,y1);
this.lineTo(x2,y2);
this.stroke();
},
//旋转绘图,使之呈菱形(45°)倾斜
rhombic(x=9,y=1){ //旋转绘图,使之呈菱形(45°)倾斜
this.scale(x,y); //缩放当前绘图 宽度
this.rotate(Math.PI * 0.25); //旋转当前绘图 45°,旋转圆心为(0,0)点。
}
});
</pre>
</div>
<div id="catalog_min">
<ul>
<li class="attrb" onclick="G('attr_canvas').scrollIntoView()">canvas</li>
<li class="attrb" onclick="G('attr_fillstyle').scrollIntoView()">fillStyle</li>
<li class="attrb" onclick="G('attr_filter').scrollIntoView()">filter</li>
<li class="attrb" onclick="G('attr_font').scrollIntoView()">font</li>
<li class="attrb" onclick="G('attr_globalalpha').scrollIntoView()">globalAlpha</li>
<li class="attrb" onclick="G('attr_globalcompositeoperation').scrollIntoView()">globalCompositeOperation</li>
<li class="attrb" onclick="G('attr_imagesmoothingenabled').scrollIntoView()">imageSmoothingEnabled</li>
<li class="attrb" onclick="G('attr_imagesmoothingquality').scrollIntoView()">imageSmoothingQuality</li>
<li class="attrb" onclick="G('attr_linecap').scrollIntoView()">lineCap</li>
<li class="attrb" onclick="G('attr_linedashoffset').scrollIntoView()">lineDashOffset</li>
<li class="attrb" onclick="G('attr_linejoin').scrollIntoView()">lineJoin</li>
<li class="attrb" onclick="G('attr_linewidth').scrollIntoView()">lineWidth</li>
<li class="attrb" onclick="G('attr_miterlimit').scrollIntoView()">miterLimit</li>
<li class="attrb" onclick="G('attr_shadowblur').scrollIntoView()">shadowBlur</li>
<li class="attrb" onclick="G('attr_shadowcolor').scrollIntoView()">shadowColor</li>
<li class="attrb" onclick="G('attr_shadowoffsetx').scrollIntoView()">shadowOffsetX</li>
<li class="attrb" onclick="G('attr_shadowoffsety').scrollIntoView()">shadowOffsetY</li>
<li class="attrb" onclick="G('attr_strokestyle').scrollIntoView()">strokeStyle</li>
<li class="attrb" onclick="G('attr_textalign').scrollIntoView()">textAlign</li>
<li class="attrb" onclick="G('attr_textbaseline').scrollIntoView()">textBaseline</li>
<li class="func" onclick="G('fun_arc').scrollIntoView()">arc</li>
<li class="func" onclick="G('fun_arcto').scrollIntoView()">arcTo</li>
<li class="func" onclick="G('fun_beginpath').scrollIntoView()">beginPath</li>
<li class="func" onclick="G('fun_beziercurveto').scrollIntoView()">bezierCurveTo</li>
<li class="func" onclick="G('fun_clearrect').scrollIntoView()">clearRect</li>
<li class="func" onclick="G('fun_clip').scrollIntoView()">clip</li>
<li class="func" onclick="G('fun_closepath').scrollIntoView()">closePath</li>
<li class="func" onclick="G('fun_constructor').scrollIntoView()">constructor</li>
<li class="func" onclick="G('fun_createimagedata').scrollIntoView()">createImageData</li>
<li class="func" onclick="G('fun_createlineargradient').scrollIntoView()">createLinearGradient</li>
<li class="func" onclick="G('fun_createpattern').scrollIntoView()">createPattern</li>
<li class="func" onclick="G('fun_createradialgradient').scrollIntoView()">createRadialGradient</li>
<li class="func" onclick="G('fun_drawfocusifneeded').scrollIntoView()">drawFocusIfNeeded</li>
<li class="func" onclick="G('fun_drawimage').scrollIntoView()">drawImage</li>
<li class="func" onclick="G('fun_ellipse').scrollIntoView()">ellipse</li>
<li class="func" onclick="G('fun_fill').scrollIntoView()">fill</li>
<li class="func" onclick="G('fun_fillrect').scrollIntoView()">fillRect</li>
<li class="func" onclick="G('fun_filltext').scrollIntoView()">fillText</li>
<li class="func" onclick="G('fun_getcontextattributes').scrollIntoView()">getContextAttributes</li>
<li class="func" onclick="G('fun_getimagedata').scrollIntoView()">getImageData</li>
<li class="func" onclick="G('fun_getlinedash').scrollIntoView()">getLineDash</li>
<li class="func" onclick="G('fun_ispointinpath').scrollIntoView()">isPointInPath</li>
<li class="func" onclick="G('fun_ispointinstroke').scrollIntoView()">isPointInStroke</li>
<li class="func" onclick="G('fun_lineto').scrollIntoView()">lineTo</li>
<li class="func" onclick="G('fun_measuretext').scrollIntoView()">measureText</li>
<li class="func" onclick="G('fun_moveto').scrollIntoView()">moveTo</li>
<li class="func" onclick="G('fun_putimagedata').scrollIntoView()">putImageData</li>
<li class="func" onclick="G('fun_quadraticcurveto').scrollIntoView()">quadraticCurveTo</li>
<li class="func" onclick="G('fun_rect').scrollIntoView()">rect</li>
<li class="func" onclick="G('fun_resettransform').scrollIntoView()">resetTransform</li>
<li class="func" onclick="G('fun_restore').scrollIntoView()">restore</li>
<li class="func" onclick="G('fun_rotate').scrollIntoView()">rotate</li>
<li class="func" onclick="G('fun_save').scrollIntoView()">save</li>
<li class="func" onclick="G('fun_scale').scrollIntoView()">scale</li>
<li class="func" onclick="G('fun_setlinedash').scrollIntoView()">setLineDash</li>
<li class="func" onclick="G('fun_settransform').scrollIntoView()">setTransform</li>
<li class="func" onclick="G('fun_stroke').scrollIntoView()">stroke</li>
<li class="func" onclick="G('fun_strokerect').scrollIntoView()">strokeRect</li>
<li class="func" onclick="G('fun_stroketext').scrollIntoView()">strokeText</li>
<li class="func" onclick="G('fun_transform').scrollIntoView()">transform</li>
<li class="func" onclick="G('fun_translate').scrollIntoView()">translate</li>
</ul>
<ul>
<li onclick="G('catalog__').scrollIntoView()">描述</li>
<li onclick="G('catalog_0').scrollIntoView()">canvas 状态</li>
<li onclick="G('catalog_1').scrollIntoView()">颜色、样式和阴影</li>
<li onclick="G('catalog_2').scrollIntoView()">线条、虚线样式</li>
<li onclick="G('catalog_3').scrollIntoView()">矩形</li>
<li onclick="G('catalog_4').scrollIntoView()">路径</li>
<li onclick="G('catalog_5').scrollIntoView()">变换</li>
<li onclick="G('catalog_6').scrollIntoView()">文本</li>
<li onclick="G('catalog_7').scrollIntoView()">图像绘制</li>
<li onclick="G('catalog_8').scrollIntoView()">像素操作</li>
<li onclick="G('catalog_9').scrollIntoView()">合成</li>
<li onclick="G('catalog_10').scrollIntoView()">点击区域</li>
<li onclick="G('ext_func').scrollIntoView()">扩展函数</li>
<li><a href="canvas-testdraw.html">testdraw(尝试一下)</a></li>
</ul>
</div>
</div>
<!------------------------------------------>
<div id="DetailContent" style="display:none">
<div id="canvas-fillstyle" class="article-detail article-body">
<h2>定义和用法</h2>
<p>fillStyle 属性设置或返回用于填充绘画的颜色、渐变或模式。</p>
<table class="tecspec">
<tbody><tr>
<th style="width:25%">默认值：</th>
<td width="75%">#000000</td>
</tr>
<tr>
<th>JavaScript 语法：</th>
<td>
<i>context</i>.fillStyle=<i>color</i>|<i>gradient</i>|<i>pattern</i>;</td>
</tr>
</tbody></table>
<h2>属性值</h2>
<table class="reference">
<tbody><tr>
<th style="width:15%">值</th>
<th>描述</th>
</tr>
<tr>
<td><i>color</i></td>
<td>指示绘图填充色的 <a href="http://www.runoob.com/cssref/css-colors-legal.html">CSS 颜色值</a>。默认值是 #000000。</td>
</tr>
<tr>
<td><i>gradient</i></td>
<td>用于填充绘图的渐变对象（<a href="canvas-createlineargradient.html">线性</a>
或 <a href="canvas-createradialgradient.html">放射性</a>）。</td>
</tr>
<tr>
<td><i>pattern</i></td>
<td>用于填充绘图的 <a href="canvas-createpattern.html">pattern</a> 对象。</td>
</tr>
</tbody></table>
<div class="example">
<h2 class="example">实例</h2>
<p>定义从上到下的渐变，作为矩形的填充样式：</p>
<canvas id="canvas-fillstyle-myCanvas2" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">
浏览器不支持Canvas标签.</canvas>
<script>
(function(){
var canvas=G("canvas-fillstyle-myCanvas2");
var ctx=canvas.getContext("2d");
var my_gradient=ctx.createLinearGradient(0,0,0,170);
my_gradient.addColorStop(0,"black");
my_gradient.addColorStop(1,"white");
ctx.fillStyle=my_gradient;
ctx.fillRect(20,20,150,100);
})();
</script>
<p>JavaScript：</p>
<div class="example_code">
var c=document.getElementById("myCanvas");<br>
var ctx=c.getContext("2d");<br>
var my_gradient=ctx.createLinearGradient(0,0,0,170);<br>
my_gradient.addColorStop(0,"black");<br>
my_gradient.addColorStop(1,"white");<br>
ctx.fillStyle=my_gradient;<br>
ctx.fillRect(20,20,150,100);
</div>
<br><a class="tryitbtn" href="http://www.runoob.com/try/try.php?filename=tryhtml5_canvas_fillstyle_gradient" target="_blank">尝试一下 »</a>
</div>
<div class="example">
<h2 class="example">实例</h2>
<p>定义从左到右的渐变，作为矩形的填充样式：</p>
<canvas id="canvas-fillstyle-myCanvas3" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">
浏览器不支持Canvas标签.</canvas>
<script>
(function(){
var canvas=G("canvas-fillstyle-myCanvas3");
var ctx=canvas.getContext("2d");
var my_gradient=ctx.createLinearGradient(0,0,170,0);
my_gradient.addColorStop(0,"black");
my_gradient.addColorStop(1,"white");
ctx.fillStyle=my_gradient;
ctx.fillRect(20,20,150,100);
})();
</script>
<p>JavaScript：</p>
<div class="example_code">
var c=document.getElementById("myCanvas");<br>
var ctx=c.getContext("2d");<br>
var my_gradient=ctx.createLinearGradient(0,0,170,0);<br>
my_gradient.addColorStop(0,"black");<br>
my_gradient.addColorStop(1,"white");<br>
ctx.fillStyle=my_gradient;<br>
ctx.fillRect(20,20,150,100);
</div>
<br><a class="tryitbtn" href="http://www.runoob.com/try/try.php?filename=tryhtml5_canvas_fillstyle_gradient2" target="_blank">尝试一下 »</a>
</div>
<div class="example">
<h2 class="example">实例</h2>
<p>定义从黑到红到白的的渐变，作为矩形的填充样式：</p>
<canvas id="canvas-fillstyle-myCanvas4" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">浏览器不支持Canvas标签.</canvas>
<script>
(function(){
var canvas=G("canvas-fillstyle-myCanvas4");
var ctx=canvas.getContext("2d");
var my_gradient=ctx.createLinearGradient(0,0,170,0);
my_gradient.addColorStop(0,"black");
my_gradient.addColorStop(0.5,"red");
my_gradient.addColorStop(1,"white");
ctx.fillStyle=my_gradient;
ctx.fillRect(20,20,150,100);
})();
</script>
<p>JavaScript：</p>
<div class="example_code">
var c=document.getElementById("myCanvas");<br>
var ctx=c.getContext("2d");<br>
var my_gradient=ctx.createLinearGradient(0,0,170,0);<br>
my_gradient.addColorStop(0,"black");<br>
my_gradient.addColorStop(0.5,"red");<br>
my_gradient.addColorStop(1,"white");<br>
ctx.fillStyle=my_gradient;<br>
ctx.fillRect(20,20,150,100);
</div>
<br><a class="tryitbtn" href="http://www.runoob.com/try/try.php?filename=tryhtml5_canvas_fillstyle_gradient3" target="_blank">尝试一下 »</a>
</div>
<div class="example">
<h2 class="example">用到的图像：</h2>
<p><img src="http://www.runoob.com/images/lamp.jpg" id="canvas-fillstyle-lamp" alt="Lamp"></p>
<h2 class="example">实例</h2>
<p>使用图像来填充绘图：</p>
<canvas id="canvas-fillstyle-myCanvas5" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">不支持Canvas标签.</canvas>
<script>
G("canvas-fillstyle-lamp").onload=function()
{
var c=G("canvas-fillstyle-myCanvas5");
var ctx=c.getContext('2d');
var img=this;
var pat=ctx.createPattern(img,'repeat');
ctx.rect(0,0,150,100);
ctx.fillStyle=pat;
ctx.fill();
}
</script>
<p>JavaScript：</p>
<div class="example_code">
var c=document.getElementById("myCanvas");<br>var ctx=c.getContext("2d");<br>
var img=document.getElementById("lamp");<br>var
pat=ctx.createPattern(img,"repeat");<br>ctx.rect(0,0,150,100);<br>
ctx.fillStyle=pat;<br>ctx.fill();</div>
<br><a class="tryitbtn" href="http://www.runoob.com/try/try.php?filename=tryhtml5_canvas_createpattern" target="_blank">尝试一下 »</a>
</div>
</div>
<div id="canvas-strokestyle" class="article-detail article-body">
<h2>定义和用法</h2>
<p>strokeStyle 属性设置或返回用于笔触的颜色、渐变或模式。</p>
<table class="tecspec">
<tbody><tr>
<th style="width:25%">默认值：</th>
<td width="75%">#000000</td>
</tr>
<tr>
<th>JavaScript 语法：</th>
<td>
<i>context</i>.strokeStyle=<i>color</i>|<i>gradient</i>|<i>pattern</i>;</td>
</tr>
</tbody></table>
<h2>属性值</h2>
<table class="reference">
<tbody><tr>
<th style="width:15%">值</th>
<th>描述</th>
</tr>
<tr>
<td><i>color</i></td>
<td>指示绘图笔触颜色的 <a href="http://www.runoob.com/cssref/css-colors-legal.html">CSS 颜色值</a>。默认值是 #000000。</td>
</tr>
<tr>
<td><i>gradient</i></td>
<td>用于填充绘图的渐变对象（<a href="canvas-createlineargradient.html">线性</a>
或 <a href="canvas-createradialgradient.html">放射性</a>）。</td>
</tr>
<tr>
<td><i>pattern</i></td>
<td>用于创建 pattern 笔触的 <a href="canvas-createpattern.html">pattern</a> 对象。</td>
</tr>
</tbody></table>
<div class="example">
<h2 class="example">实例</h2>
<p>绘制一个矩形。使用渐变笔触：</p>
<canvas id="canvas-strokestyle-myCanvas2" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">不支持Canvas标签.</canvas>
<script>
(function(){
var c=G("canvas-strokestyle-myCanvas2");
var ctx=c.getContext("2d");
var gradient=ctx.createLinearGradient(0,0,170,0);
gradient.addColorStop("0","magenta");
gradient.addColorStop("0.5","blue");
gradient.addColorStop("1.0","red");
// Fill with gradient
ctx.lineWidth=5;
ctx.strokeStyle=gradient;
ctx.strokeRect(20,20,150,100);
})();
</script>
<p>JavaScript：</p>
<div class="example_code">
var c=document.getElementById("myCanvas");<br>
var ctx=c.getContext("2d");<br><br>
var gradient=ctx.createLinearGradient(0,0,170,0);<br>
gradient.addColorStop("0","magenta");<br>
gradient.addColorStop("0.5","blue");<br>
gradient.addColorStop("1.0","red");<br><br>
// Fill with gradient<br>
ctx.strokeStyle=gradient;<br>
ctx.lineWidth=5;<br>
ctx.strokeRect(20,20,150,100);
</div>
<br><a class="tryitbtn" href="http://www.runoob.com/try/try.php?filename=tryhtml5_canvas_strokestyle2" target="_blank">尝试一下 »</a>
</div>
<div class="example">
<h2 class="example">实例</h2>
<p>用一个渐变笔触来写文本 "Big smile!"：</p>
<canvas id="canvas-strokestyle-myCanvas3" width="300" height="150" style="border:1px solid #d3d3d3;background:#ffffff;">不支持Canvas标签.</canvas>
<script>
(function(){
var c=G("canvas-strokestyle-myCanvas3");
var ctx=c.getContext("2d");
ctx.font="30px Verdana";
// Create gradient
var gradient=ctx.createLinearGradient(0,0,c.width,0);
gradient.addColorStop("0","magenta");
gradient.addColorStop("0.5","blue");
gradient.addColorStop("1.0","red");
// Fill with gradient
ctx.strokeStyle=gradient;
ctx.strokeText("Big smile!",10,50);
})();