Procedura: creare un disegno composto

Articolo
09/12/2008

Aggiornamento: novembre 2007

In questo esempio viene illustrato come utilizzare DrawingGroup per creare disegni complessi combinando più oggetti Drawing in un solo disegno composto.

Esempio

Nell'esempio riportato di seguito viene utilizzato DrawingGroup per creare un disegno composto dagli oggetti GeometryDrawing e ImageDrawing. Nella figura riportata di seguito viene illustrato l'output che si ottiene dall'esempio.

Disegno composto creato utilizzando DrawingGroup

DrawingGroup con più disegni

Si noti il bordo grigio che indica i limiti del disegno.

//
// 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>

È possibile utilizzare DrawingGroup per applicare Transform, un'impostazione di Opacity, OpacityMask, BitmapEffect, ClipGeometry o GuidelineSet ai disegni che contiene. Poiché DrawingGroup è anche Drawing, può contenere altri oggetti DrawingGroup.

L'esempio riportato di seguito è simile a quello precedente, tranne per il fatto che vengono utilizzati altri oggetti DrawingGroup per applicare effetti bitmap e una maschera di opacità ad alcuni dei disegni. Nella figura riportata di seguito viene illustrato l'output che si ottiene dall'esempio.

Disegno composto con più oggetti DrawingGroup

DrawingGroup con più disegni

Si noti il bordo grigio che indica i limiti del disegno.

// 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>

Per ulteriori informazioni sugli oggetti Drawing, vedere Cenni preliminari sugli oggetti Drawing.