Allow to not show Grid Lines on Charts

[amitaypb]

Hello,

I am using your Charts and I would like to have the possibility to be able to hide and show the Grid Lines of Charts.
I was checking your code and when getting the Axes of a Chart, you are setting the axis.ShowGridLines = true (this is done on the protected override void GetAxes(DataPoint firstDataPoint) method)

Can you please add a ShowGridLines dependency Property to the DataPointSingleSeriesWithAxes class and use it on the GetAxes method of each Chart?

For instance:

On DataPointSingleSeriesWithAxes class:

///

/// Gets or sets a value indicating whether grid lines should be shown.
///

[SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "GridLines", Justification = "This is the expected casing.")]
public bool ShowGridLines
{
get { return (bool)GetValue(ShowGridLinesProperty); }
set { SetValue(ShowGridLinesProperty, value); }
}

    /// <summary>
    /// Identifies the ShowGridLines dependency property.
    /// </summary>
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "GridLines", Justification = "This is the expected capitalization.")]
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "GridLine", Justification = "This is the expected capitalization.")]
    public static readonly DependencyProperty ShowGridLinesProperty =
        DependencyProperty.Register(
            "ShowGridLines",
            typeof(bool),
            typeof(DataPointSingleSeriesWithAxes),
            new PropertyMetadata(true));

And on ColumnSeries.cs, BarSeries.cs, etc

protected override void GetAxes(DataPoint firstDataPoint)
{
...
if (axis != null)
{
axis.ShowGridLines = ShowGridLines; //Use the value of the Dependency Property
}
...
}

With that, we can do something like (To hide the Grid Lines):
<chartingToolkit:ColumnSeries Grid.Row="0"
Grid.Column="0"
DependentValuePath="Value"
IndependentValuePath="Key"
ItemsSource="{Binding Data}"
ShowGridLines="False"/>

[icehoo]

您好，我现在正在忙，可能无法亲自回复您的邮件。我将以最快的速度，尽快给您回复。 

[jogibear9988]

if you create a pull req for this, i will merge