上一篇，已简单介绍Clip属性的用法，这一篇用它来实现简单蒙板功能，很简单，直接上代码
<Window x:Class="擦除效果.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="537" Width="866" MouseMove="canvas_MouseMove" MouseDown="Window_MouseDown" MouseUp="Window_MouseUp">
<Grid>
<Rectangle Height="100" HorizontalAlignment="Left" Margin="164,92,0,0" Name="rectangle1" Stroke="Black" VerticalAlignment="Top" Width="200" Fill="Lime" />
<Button Content="Button" Height="83" HorizontalAlignment="Left" Margin="526,109,0,0" Name="button1" VerticalAlignment="Top" Width="115" Click="button1_Click" />
<Grid x:Name="grid" Background="#88FFFFFF" ></Grid>
</Grid>
<Window.Background>
<ImageBrush ImageSource="/擦除效果;component/Images/s01.jpg" />
</Window.Background>
</Window>
后台：
public partial class MainWindow : Window
{
private bool isDown = false;
public MainWindow()
{
InitializeComponent();
RectangleGeometry rg = new RectangleGeometry();
rg.Rect = new Rect(0, 0, this.Width, this.Height);
gridGeometry = Geometry.Combine(gridGeometry, rg, GeometryCombineMode.Union, null);
grid.Clip = gridGeometry;
}
PathGeometry gridGeometry = new PathGeometry();
private void canvas_MouseMove(object sender, MouseEventArgs e)
{
if (isDown)
{
EllipseGeometry rg = new EllipseGeometry();
rg.Center = e.GetPosition(this);
rg.RadiusX = 50;
rg.RadiusY = 50;
//排除几何图形
gridGeometry = Geometry.Combine(gridGeometry, rg, GeometryCombineMode.Exclude, null);
grid.Clip = gridGeometry;
}
}
private void button1_Click(object sender, RoutedEventArgs e)
{
MessageBox.Show("OK!");
}
private void Window_MouseDown(object sender, MouseButtonEventArgs e)
{
isDown = true;
}
private void Window_MouseUp(object sender, MouseButtonEventArgs e)
{
isDown = false;
}
}
效果如下：
