System.Windows.Media 命名空间


.NET Framework 类库
ImageDrawing 类

更新:2007 年 11 月

在由 Rect 定义的区域内绘制图像。

命名空间:  System.Windows.Media
程序集:  PresentationCore(在 PresentationCore.dll 中)
用于 XAML 的 XMLNS:http://schemas.microsoft.com/winfx/xaml/presentation

语法

Visual Basic(声明)
Public NotInheritable Class ImageDrawing _
    Inherits Drawing
Visual Basic (用法)
Dim instance As ImageDrawing
C#
public sealed class ImageDrawing : Drawing
Visual C++
public ref class ImageDrawing sealed : public Drawing
J#
public final class ImageDrawing extends Drawing
JScript
public final class ImageDrawing extends Drawing
XAML 对象元素用法
<ImageDrawing .../>
备注

性能说明:Image 相比,DrawingImage 提供的呈现图像功能要少一些,但 DrawingImage 提供的性能具有一定的优势,是使用 Visual 对象对背景、剪贴画进行低级别绘制的理想选择。有关更多信息,请参见Drawing 对象概述

ImageDrawing 是一种 Freezable 对象,因此可以将它冻结以提高性能。有关 Freezable 功能(例如冻结和克隆)的信息,请参见 Freezable 对象概述

示例

本示例演示如何使用 ImageDrawing 来绘制图像。使用 ImageDrawing,可以借助于 DrawingBrushDrawingImageVisual 来显示 ImageSource。若要绘制图像,请创建一个 ImageDrawing 并设置它的 ImageDrawing..::.ImageSourceImageDrawing..::.Rect 属性。ImageDrawing..::.ImageSource 属性指定要绘制的图像,ImageDrawing..::.Rect 属性指定每个图像的位置和大小。

下面的示例使用四个 ImageDrawing 对象创建一个复合绘图。该示例生成下面的图像:

四个 ImageDrawing 对象

几个 DrawingImage 对象
C#
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.Imaging;

namespace SDKSample
{
    public class ImageDrawingExample : Page
    {
        public ImageDrawingExample()
        {
            // Create a DrawingGroup to combine the ImageDrawing objects.
            DrawingGroup imageDrawings = new DrawingGroup();

            // Create a 100 by 100 image with an upper-left point of (75,75). 
            ImageDrawing bigKiwi = new ImageDrawing();
            bigKiwi.Rect = new Rect(75, 75, 100, 100);
            bigKiwi.ImageSource = new BitmapImage(
                new Uri(@"sampleImages\kiwi.png", UriKind.Relative));

            imageDrawings.Children.Add(bigKiwi);

            // Create a 25 by 25 image with an upper-left point of (0,150). 
            ImageDrawing smallKiwi1 = new ImageDrawing();
            smallKiwi1.Rect = new Rect(0, 150, 25, 25);
            smallKiwi1.ImageSource = new BitmapImage(new Uri(@"sampleImages\kiwi.png", UriKind.Relative));
            imageDrawings.Children.Add(smallKiwi1);

            // Create a 25 by 25 image with an upper-left point of (150,0). 
            ImageDrawing smallKiwi2 = new ImageDrawing();
            smallKiwi2.Rect = new Rect(150, 0, 25, 25);
            smallKiwi2.ImageSource = new BitmapImage(new Uri(@"sampleImages\kiwi.png", UriKind.Relative));
            imageDrawings.Children.Add(smallKiwi2);

            // Create a 75 by 75 image with an upper-left point of (0,0). 
            ImageDrawing wholeKiwi = new ImageDrawing();
            wholeKiwi.Rect = new Rect(0, 0, 75, 75);
            wholeKiwi.ImageSource = new BitmapImage(new Uri(@"sampleImages\wholekiwi.png", UriKind.Relative));
            imageDrawings.Children.Add(wholeKiwi);

            //
            // Use a DrawingImage and an Image control to
            // display the drawings.
            //
            DrawingImage drawingImageSource = new DrawingImage(imageDrawings);

            // Freeze the DrawingImage for performance benefits.
            drawingImageSource.Freeze();

            Image imageControl = new Image();
            imageControl.Stretch = Stretch.None;
            imageControl.Source = drawingImageSource;

            // Create a border to contain the Image control.
            Border imageBorder = new Border();
            imageBorder.BorderBrush = Brushes.Gray;
            imageBorder.BorderThickness = new Thickness(1);
            imageBorder.HorizontalAlignment = HorizontalAlignment.Left;
            imageBorder.VerticalAlignment = VerticalAlignment.Top;
            imageBorder.Margin = new Thickness(20);
            imageBorder.Child = imageControl;

            this.Background = Brushes.White;
            this.Margin = new Thickness(20);
            this.Content = imageBorder;
        }

    }
}
XAML
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
  xmlns:PresentationOptions="http://schemas.microsoft.com/winfx/2006/xaml/presentation/options" 
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="PresentationOptions"
  Background="White" Margin="20">
  <Border BorderBrush="Gray" BorderThickness="1" 
    HorizontalAlignment="Left" VerticalAlignment="Top"
    Margin="20">
    <Image Stretch="None">
      <Image.Source>
        <DrawingImage PresentationOptions:Freeze="True">
          <DrawingImage.Drawing>
            <DrawingGroup>

              <!-- The Rect property specifies that the image only fill a 100 by 100
                   rectangular area. -->
              <ImageDrawing Rect="75,75,100,100" ImageSource="sampleImages\kiwi.png"/>

              <!-- This image is set to fill a 25 by 25 rectangular area. -->
              <ImageDrawing Rect="0,150,25,25" ImageSource="sampleImages\kiwi.png"/>

              <!-- This image is set to fill a 25 by 25 rectangular area. -->
              <ImageDrawing Rect="150,0,25,25" ImageSource="sampleImages\kiwi.png"/>

              <!-- This image is set to fill a 75 by 75 rectangular area. -->
              <ImageDrawing Rect="0,0,75,75" ImageSource="sampleImages\wholekiwi.png"/>

            </DrawingGroup>
          </DrawingImage.Drawing>
        </DrawingImage>
      </Image.Source>
    </Image>
  </Border>
</Page>

有关演示在不使用 ImageDrawing 的情况下显示图像的简单方法的示例,请参见如何:使用 Image 元素

继承层次结构

System..::.Object
  System.Windows.Threading..::.DispatcherObject
    System.Windows..::.DependencyObject
      System.Windows..::.Freezable
        System.Windows.Media.Animation..::.Animatable
          System.Windows.Media..::.Drawing
            System.Windows.Media..::.ImageDrawing
线程安全

此类型的任何公共 static(在 Visual Basic 中为 Shared) 成员都是线程安全的。但不保证所有实例成员都是线程安全的。
平台

Windows Vista

.NET Framework 和 .NET Compact Framework 并不是对每个平台的所有版本都提供支持。有关支持的版本的列表,请参见.NET Framework 系统要求

版本信息

.NET Framework

受以下版本支持:3.5、3.0
另请参见

参考

其他资源

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