Como: Aplicar Um Efeito de Bitmap em um Desenho
Este exemplo mostra como aplicar um BitmapEffect em um desenho. Use um BitmapEffect para embaçar ou embaralhar, ou aplique outro efeito visual ao conteúdo renderizado.
Somente objetos DrawingGroup suportam efeitos de bitmap. Para aplicar um efeito de bitmap em outro tipo de objeto Drawing, adicione-o para o DrawingGroup e defina a propriedade BitmapEffect do objeto DrawingGroup.
.gif "Observação") Observação: |
|---|
Windows Presentation Foundation (WPF) efeitos de bitmap são renderizados por software. Qualquer objeto que aplica um BitmapEffect também é renderizado no software. Evite usar um BitmapEffect em grandes animações ou visuais porque este cenário pode causar um decréscimo da performance do sistema. |
Exemplo
O seguinte exemplo usa um DrawingGroup para aplicar um BlurBitmapEffect para vários objetos GeometryDrawing.
A seguinte ilustração mostra a saúda deste exemplo.
.png "DrawingGroup com um BlurBitmapEffect")
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>
Consulte também
Conceitos
Visão Geral de Objetos de Desenho
Visão Geral de Efeitos de Bitmap
Visão geral sobre objetos Freezable