UIElement.OpacityMask Property
Assembly: PresentationCore (in presentationcore.dll)
XML Namespace: http://schemas.microsoft.com/winfx/2006/xaml/presentation
This property only uses whatever the alpha channel value is for the supplied Brush. The other channels of the Brush's rendered content (Red, Green, or Blue) are ignored.
The most typical Brush for this purpose is an ImageBrush, which can be used for a variety of photo masking techniques such as a vignette. But any defined Brush (such as LinearGradientBrush) can be used.
In Extensible Application Markup Language (XAML), this property value can use an inline syntax that is specific to each implementation of the Brush abstract class. For more information, see WPF Brushes Overview.
The following markup example shows an ImageBrush opacity mask applied to another Image.
<!-- With the Opacity Mask--> <Image Height="150" Width="200" Source="sampleImages/Waterlilies.jpg" HorizontalAlignment="Left" Margin="10" Grid.Column="2" Grid.Row="1"> <Image.OpacityMask> <ImageBrush ImageSource="sampleImages/tornedges.png"/> </Image.OpacityMask> </Image>
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.Reference
UIElement ClassUIElement Members
System.Windows Namespace
Opacity