Comment : appliquer un BitmapEffect à un dessin
Mise à jour : novembre 2007
Cet exemple montre comment appliquer un BitmapEffect à un dessin. Utilisez un BitmapEffect pour brouiller, donner du relief ou appliquer d'autres effets visuels au contenu rendu.
Seuls les objets DrawingGroup prennent en charge les effets bitmap. Pour appliquer un effet bitmap à un autre type d'objet Drawing, ajoutez-le à un DrawingGroup et définissez la propriété BitmapEffect de l'objet DrawingGroup.
.gif "Remarque") Remarque : |
|---|
Les effets bitmap Windows Presentation Foundation (WPF) sont restitués par logiciel. Tout objet qui applique un BitmapEffect est également restitué dans le logiciel. Évitez d'utiliser un BitmapEffect dans les effets visuels ou les animations importants, car ce scénario peut provoquer une diminution des performances système. |
Exemple
L'exemple suivant utilise un DrawingGroup pour appliquer un BlurBitmapEffect à plusieurs objets GeometryDrawing.
L'illustration suivante indique la sortie de cet exemple.
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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>
Voir aussi
Concepts
Vue d'ensemble des objets Drawing
Vue d'ensemble des effets bitmap
Vue d'ensemble des objets Freezable