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UIElement.OpacityMask Property

Gets or sets an opacity mask, as a Brush implementation that is applied to any alpha-channel masking for the rendered content of this element. This is a dependency property.

Namespace: System.Windows
Assembly: PresentationCore (in presentationcore.dll)
XML Namespace:  http://schemas.microsoft.com/winfx/2006/xaml/presentation

public Brush OpacityMask { get; set; }
/** @property */
public Brush get_OpacityMask ()

/** @property */
public void set_OpacityMask (Brush value)

public function get OpacityMask () : Brush

public function set OpacityMask (value : Brush)

For XAML information, see the Brush type.

Property Value

The brush to use for opacity masking.

Identifier field

OpacityMaskProperty

Metadata properties set to true

None

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.

.NET Framework

Supported in: 3.0
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