如何：创建复合绘图

此示例演示如何使用 DrawingGroup 来通过将多个 Drawing 对象组合到单个复合绘图中来创建复杂的绘图。

示例

以下示例使用 DrawingGroup 从 GeometryDrawing 和 ImageDrawing 对象创建复合绘图。 下图显示了此示例生成的输出。

使用 DrawingGroup 创建的复合绘图

请注意灰色边框，它显示了绘图的边界。

//
// Create three drawings.
//
GeometryDrawing ellipseDrawing =
    new GeometryDrawing(
        new SolidColorBrush(Color.FromArgb(102, 181, 243, 20)),
        new Pen(Brushes.Black, 4),
        new EllipseGeometry(new Point(50,50), 50, 50)
    );

ImageDrawing kiwiPictureDrawing =
    new ImageDrawing(
        new BitmapImage(new Uri(@"sampleImages\kiwi.png", UriKind.Relative)),
        new Rect(50,50,100,100));

GeometryDrawing ellipseDrawing2 =
    new GeometryDrawing(
        new SolidColorBrush(Color.FromArgb(102,181,243,20)),
        new Pen(Brushes.Black, 4),
        new EllipseGeometry(new Point(150, 150), 50, 50)
    );

// Create a DrawingGroup to contain the drawings.
DrawingGroup aDrawingGroup = new DrawingGroup();
aDrawingGroup.Children.Add(ellipseDrawing);
aDrawingGroup.Children.Add(kiwiPictureDrawing);
aDrawingGroup.Children.Add(ellipseDrawing2);

<DrawingGroup>

  <GeometryDrawing Brush="#66B5F314">
    <GeometryDrawing.Geometry>
      <EllipseGeometry Center="50,50" RadiusX="50"  RadiusY="50"/>
    </GeometryDrawing.Geometry>
    <GeometryDrawing.Pen>
      <Pen Brush="Black" Thickness="4" />
    </GeometryDrawing.Pen>
  </GeometryDrawing>
  <ImageDrawing ImageSource="sampleImages\kiwi.png" Rect="50,50,100,100"/>
  <GeometryDrawing Brush="#66B5F314">
    <GeometryDrawing.Geometry>
      <EllipseGeometry Center="150,150" RadiusX="50"  RadiusY="50"/>
    </GeometryDrawing.Geometry>
    <GeometryDrawing.Pen>
      <Pen Brush="Black" Thickness="4" />
    </GeometryDrawing.Pen>
  </GeometryDrawing>
</DrawingGroup>

可以使用 DrawingGroup 将 Transform、Opacity 设置、OpacityMask、BitmapEffect、ClipGeometry 或GuidelineSet 应用到其包含的绘图中。 由于 DrawingGroup 也是 Drawing，因此它可以包含其他 DrawingGroup 对象。

以下示例与前面的示例类似，只不过它使用其他 DrawingGroup 对象来将位图效果和不透明度蒙板应用到某些绘图中。 下图显示了此示例生成的输出。

具有多个 DrawingGroup 对象的复合绘图

请注意灰色边框，它显示了绘图的边界。

// Create a DrawingGroup.
DrawingGroup mainGroup = new DrawingGroup();

//
// Create a GeometryDrawing
//
GeometryDrawing ellipseDrawing =
    new GeometryDrawing(
        new SolidColorBrush(Color.FromArgb(102, 181, 243, 20)),
        new Pen(Brushes.Black, 4),
        new EllipseGeometry(new Point(50, 50), 50, 50)
    );

//
// Use a DrawingGroup to apply a blur
// bitmap effect to the drawing.
//
DrawingGroup blurGroup = new DrawingGroup();
blurGroup.Children.Add(ellipseDrawing);
BlurBitmapEffect blurEffect = new BlurBitmapEffect();
blurEffect.Radius = 5;
blurGroup.BitmapEffect = blurEffect;

// Add the DrawingGroup to the main DrawingGroup.
mainGroup.Children.Add(blurGroup);

//
// Create an ImageDrawing.
//
ImageDrawing kiwiPictureDrawing =
    new ImageDrawing(
        new BitmapImage(new Uri(@"sampleImages\kiwi.png", UriKind.Relative)),
        new Rect(50, 50, 100, 100));

//
// Use a DrawingGroup to apply an opacity mask
// and a bevel.
//
DrawingGroup maskedAndBeveledGroup = new DrawingGroup();
maskedAndBeveledGroup.Children.Add(kiwiPictureDrawing);

// Create an opacity mask.
RadialGradientBrush rgBrush =new RadialGradientBrush();
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(0,0,0,0), 0.55));
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(255,0,0,0), 0.65));
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(0,0,0,0), 0.75));
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(255,0,0,0), 0.80));
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(0,0,0,0), 0.90));
rgBrush.GradientStops.Add(new GradientStop(Color.FromArgb(255,0,0,0), 1.0));
maskedAndBeveledGroup.OpacityMask = rgBrush;

// Apply a bevel.
maskedAndBeveledGroup.BitmapEffect = new BevelBitmapEffect();

// Add the DrawingGroup to the main group.
mainGroup.Children.Add(maskedAndBeveledGroup);

//
// Create another GeometryDrawing.
//
GeometryDrawing ellipseDrawing2 =
  new GeometryDrawing(
      new SolidColorBrush(Color.FromArgb(102, 181, 243, 20)),
      new Pen(Brushes.Black, 4),
      new EllipseGeometry(new Point(150, 150), 50, 50)
  );

// Add the DrawingGroup to the main group.
mainGroup.Children.Add(ellipseDrawing2);

<DrawingGroup>

  <DrawingGroup>
    <GeometryDrawing Brush="#66B5F314">
      <GeometryDrawing.Geometry>
        <EllipseGeometry Center="50,50" RadiusX="50"  RadiusY="50"/>
      </GeometryDrawing.Geometry>
      <GeometryDrawing.Pen>
        <Pen Brush="Black" Thickness="4" />
      </GeometryDrawing.Pen>
    </GeometryDrawing>
    <DrawingGroup.BitmapEffect>
      <BlurBitmapEffect Radius="5" />
    </DrawingGroup.BitmapEffect>
  </DrawingGroup>

  <DrawingGroup>
    <ImageDrawing ImageSource="sampleImages\kiwi.png" Rect="50,50,100,100"/>
    <DrawingGroup.BitmapEffect>
      <BevelBitmapEffect  />
    </DrawingGroup.BitmapEffect>
    <DrawingGroup.OpacityMask>
      <RadialGradientBrush>
        <GradientStop Offset="0.55" Color="#00000000" />
        <GradientStop Offset="0.65" Color="#FF000000" />
        <GradientStop Offset="0.75" Color="#00000000" />
        <GradientStop Offset="0.80" Color="#FF000000" />
        <GradientStop Offset="0.90" Color="#00000000" />
        <GradientStop Offset="1.0" Color="#FF000000" />
      </RadialGradientBrush>
    </DrawingGroup.OpacityMask>
  </DrawingGroup>

  <GeometryDrawing Brush="#66B5F314">
    <GeometryDrawing.Geometry>
      <EllipseGeometry Center="150,150" RadiusX="50"  RadiusY="50"/>
    </GeometryDrawing.Geometry>
    <GeometryDrawing.Pen>
      <Pen Brush="Black" Thickness="4" />
    </GeometryDrawing.Pen>
  </GeometryDrawing>

</DrawingGroup>

有关 Drawing 对象的详细信息，请参阅绘图对象概述。

另请参阅

• BitmapEffect
• Transform
• OpacityMask
• Opacity
• ClipGeometry
• GuidelineSet
• Drawing 对象概述