wpf之渐变色LinearGradientBrush

xmal代码：

 <Grid Name="grid1">
      <Grid.Background>
          <LinearGradientBrush>
              <LinearGradientBrush.GradientStops>
                  <GradientStop Offset="0" Color="red"></GradientStop>
                  <GradientStop Offset="0.5" Color="blue"></GradientStop>
                  <GradientStop Offset="1" Color="Yellow"></GradientStop>
              </LinearGradientBrush.GradientStops>
          </LinearGradientBrush>
      </Grid.Background>
 </Grid>

也可以用C#代码实现，等价的C#代码为：

 public MainWindow()
 {
      InitializeComponent();
      MyLinearGradientBrush();
 }

 public void MyLinearGradientBrush()
 8 {
      LinearGradientBrush brush = new LinearGradientBrush();

      GradientStop gs1 = new GradientStop();
      gs1.Offset = ;
      gs1.Color = Colors.Red;
      brush.GradientStops.Add(gs1);

      GradientStop gs2 = new GradientStop();
      gs2.Offset = 0.5;
      gs2.Color = Colors.Blue;
      brush.GradientStops.Add(gs2);

      GradientStop gs3 = new GradientStop();
      gs3.Offset = ;
      gs3.Color = Colors.Yellow;
　　　　 //因为GradientStops属性返回一个GradientStopCollection对象，而且GradientStopCollection类实现了IList接口
      brush.GradientStops.Add(gs3);//所以这句代码的本质是IList list = brush.GradientStops; list.Add(gs3);

      grid1.Background = brush;
 }