Gewusst wie: Anwenden von Bitmapeffekten auf eine Zeichnung
Aktualisiert: November 2007
In diesem Beispiel wird dargestellt, wie Sie einen BitmapEffect auf eine Zeichnung anwenden. Mithilfe eines BitmapEffect können Sie wiedergegebenen Inhalt weichzeichnen sowie geprägte oder andere visuelle Effekte anwenden.
Bitmapeffekte werden nur von DrawingGroup-Objekten unterstützt. Wenn Sie Bitmapeffekte auf andere Drawing-Objekttypen anwenden möchten, fügen Sie diese einem DrawingGroup-Objekt hinzu, und legen Sie die BitmapEffect-Eigenschaft des DrawingGroup-Objekts fest.
Tipp
Windows Presentation Foundation (WPF)-Bitmapeffekte werden in der Software gerendert. Jedes Objekt, das einen BitmapEffect anwendet, wird auch in der Software gerendert. Es wird empfohlen, in großen Grafikdarstellungen oder Animationen keinen BitmapEffect zu verwenden, da dadurch die Systemleistung beeinträchtigt werden kann.
Beispiel
Im folgenden Beispiel wird mithilfe einer DrawingGroup eine BlurBitmapEffect auf mehrere GeometryDrawing-Objekte angewendet.
Die folgende Abbildung zeigt die Ausgabe des Codebeispiels.
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using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Media.Effects;
namespace SDKSample
{
/// <summary>
/// This example creates two DrawingGroup objects,
/// one with a bitmap effect and one without.
/// </summary>
public class BitmapEffectExample : Page
{
public BitmapEffectExample()
{
//
// Create a DrawingGroup
// that has no BitmapEffect
//
PathFigure pLineFigure = new PathFigure();
pLineFigure.StartPoint = new Point(25, 25);
PolyLineSegment pLineSegment = new PolyLineSegment();
pLineSegment.Points.Add(new Point(0,50));
pLineSegment.Points.Add(new Point(25, 75));
pLineSegment.Points.Add(new Point(50, 50));
pLineSegment.Points.Add(new Point(25, 25));
pLineSegment.Points.Add(new Point(25, 0));
pLineFigure.Segments.Add(pLineSegment);
PathGeometry pGeometry = new PathGeometry();
pGeometry.Figures.Add(pLineFigure);
GeometryDrawing drawing1 = new GeometryDrawing(
Brushes.Lime,
new Pen(Brushes.Black, 10),
pGeometry
);
GeometryDrawing drawing2 = new GeometryDrawing(
Brushes.Lime,
new Pen(Brushes.Black, 2),
new EllipseGeometry(new Point(10,10), 5, 5)
);
// Create a DrawingGroup
DrawingGroup drawingGroupWithoutBitmapEffect = new DrawingGroup();
drawingGroupWithoutBitmapEffect.Children.Add(drawing1);
drawingGroupWithoutBitmapEffect.Children.Add(drawing2);
// Use an Image control and a DrawingImage to
// display the drawing.
DrawingImage drawingImage01 = new DrawingImage(drawingGroupWithoutBitmapEffect);
// Freeze the DrawingImage for performance benefits.
drawingImage01.Freeze();
Image image01 = new Image();
image01.Source = drawingImage01;
image01.Stretch = Stretch.None;
image01.HorizontalAlignment = HorizontalAlignment.Left;
//
// Create another DrawingGroup and apply
// a blur effect to it.
//
// Create a clone of the first DrawingGroup.
DrawingGroup drawingGroupWithBitmapEffect =
drawingGroupWithoutBitmapEffect.Clone();
// Create a blur effect.
BlurBitmapEffect blurEffect = new BlurBitmapEffect();
blurEffect.Radius = 3.0;
// Apply it to the drawing group.
drawingGroupWithBitmapEffect.BitmapEffect = blurEffect;
// Use another Image control and DrawingImage
// to display the drawing.
DrawingImage drawingImage02 = new DrawingImage(drawingGroupWithBitmapEffect);
// Freeze the DrawingImage for performance benefits.
drawingImage02.Freeze();
Image image02 = new Image();
image02.Source = drawingImage02;
image02.Stretch = Stretch.None;
image02.HorizontalAlignment = HorizontalAlignment.Left;
// Create borders around the images and add them to the
// page.
Border border01 = new Border();
border01.BorderBrush = Brushes.Gray;
border01.BorderThickness = new Thickness(1);
border01.VerticalAlignment = VerticalAlignment.Top;
border01.Margin = new Thickness(10);
border01.Child = image01;
Border border02 = new Border();
border02.BorderBrush = Brushes.Gray;
border02.BorderThickness = new Thickness(1);
border02.VerticalAlignment = VerticalAlignment.Top;
border02.Margin = new Thickness(50,10,10,10);
border02.Child = image02;
StackPanel mainPanel = new StackPanel();
mainPanel.Orientation = Orientation.Horizontal;
mainPanel.HorizontalAlignment = HorizontalAlignment.Left;
mainPanel.VerticalAlignment = VerticalAlignment.Top;
mainPanel.Children.Add(border01);
mainPanel.Children.Add(border02);
//
// Use a DrawingBrush to create a checkered background for the page.
//
GeometryDrawing backgroundSquareDrawing =
new GeometryDrawing(
Brushes.White,
null,
new RectangleGeometry(new Rect(0,0,1,1)));
GeometryGroup twoRectangles = new GeometryGroup();
twoRectangles.Children.Add(new RectangleGeometry(new Rect(0,0,0.5,0.5)));
twoRectangles.Children.Add(new RectangleGeometry(new Rect(0.5,0.5,0.5,0.5)));
SolidColorBrush squaresBrush =
new SolidColorBrush(Color.FromArgb(102,204,204,204));
squaresBrush.Opacity = 0.4;
GeometryDrawing checkerDrawing =
new GeometryDrawing(
squaresBrush,
null,
twoRectangles);
DrawingGroup checkerDrawings = new DrawingGroup();
checkerDrawings.Children.Add(backgroundSquareDrawing);
checkerDrawings.Children.Add(checkerDrawing);
DrawingBrush checkerBrush = new DrawingBrush(checkerDrawings);
checkerBrush.Viewport = new Rect(0,0,10,10);
checkerBrush.ViewportUnits = BrushMappingMode.Absolute;
checkerBrush.TileMode = TileMode.Tile;
checkerBrush.Freeze();
this.Background = checkerBrush;
this.Content = mainPanel;
}
}
}
<Page
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
xmlns:PresentationOptions="https://schemas.microsoft.com/winfx/2006/xaml/presentation/options"
xmlns:mc="https://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="PresentationOptions">
<StackPanel Margin="20" Orientation="Horizontal"
HorizontalAlignment="Left" VerticalAlignment="Top">
<!-- Shows the DrawingGroup without the blur effect. -->
<Border BorderBrush="Gray" BorderThickness="1" Margin="10"
VerticalAlignment="Top">
<Image Stretch="None" HorizontalAlignment="Left">
<Image.Source>
<DrawingImage PresentationOptions:Freeze="True">
<DrawingImage.Drawing>
<DrawingGroup>
<GeometryDrawing Brush="Lime" Geometry="M 25,25 L 0,50 25,75 50,50 25,25 25,0">
<GeometryDrawing.Pen>
<Pen Thickness="10" Brush="Black" />
</GeometryDrawing.Pen>
</GeometryDrawing>
<GeometryDrawing Brush="Lime">
<GeometryDrawing.Geometry>
<EllipseGeometry Center="10,10" RadiusX="5" RadiusY="5" />
</GeometryDrawing.Geometry>
<GeometryDrawing.Pen>
<Pen Thickness="2" Brush="Black" />
</GeometryDrawing.Pen>
</GeometryDrawing>
</DrawingGroup>
</DrawingImage.Drawing>
</DrawingImage>
</Image.Source>
</Image>
</Border>
<Border BorderBrush="Gray" BorderThickness="1" Margin="50,10,10,10"
VerticalAlignment="Top">
<Image Stretch="None" HorizontalAlignment="Left">
<Image.Source>
<DrawingImage PresentationOptions:Freeze="True">
<DrawingImage.Drawing>
<!-- The drawing group, with a BlurBitmapEffect. -->
<DrawingGroup>
<GeometryDrawing Brush="Lime" Geometry="M 25,25 L 0,50 25,75 50,50 25,25 25,0">
<GeometryDrawing.Pen>
<Pen Thickness="10" Brush="Black" />
</GeometryDrawing.Pen>
</GeometryDrawing>
<GeometryDrawing Brush="Lime">
<GeometryDrawing.Geometry>
<EllipseGeometry Center="10,10" RadiusX="5" RadiusY="5" />
</GeometryDrawing.Geometry>
<GeometryDrawing.Pen>
<Pen Thickness="2" Brush="Black" />
</GeometryDrawing.Pen>
</GeometryDrawing>
<DrawingGroup.BitmapEffect>
<BlurBitmapEffect Radius="5" />
</DrawingGroup.BitmapEffect>
</DrawingGroup>
</DrawingImage.Drawing>
</DrawingImage>
</Image.Source>
</Image>
</Border>
</StackPanel>
<Page.Background>
<!-- Creates a checkered background. -->
<DrawingBrush Viewport="0,0,10,10" ViewportUnits="Absolute" TileMode="Tile"
PresentationOptions:Freeze="True">
<DrawingBrush.Drawing>
<DrawingGroup>
<GeometryDrawing Brush="White">
<GeometryDrawing.Geometry>
<RectangleGeometry Rect="0 0 1 1"/>
</GeometryDrawing.Geometry>
</GeometryDrawing>
<GeometryDrawing Brush="#66CCCCCC">
<GeometryDrawing.Geometry>
<GeometryGroup>
<RectangleGeometry Rect="0 0 0.5 0.5" />
<RectangleGeometry Rect="0.5 0.5 0.5 0.5"/>
</GeometryGroup>
</GeometryDrawing.Geometry>
</GeometryDrawing>
</DrawingGroup>
</DrawingBrush.Drawing>
</DrawingBrush>
</Page.Background>
</Page>
Siehe auch
Konzepte
Übersicht über Zeichnungsobjekte
Übersicht über Freezable-Objekte