UIElement.OpacityMask Property

Definition

Namespace:

System.Windows

Assembly:

PresentationCore.dll

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.

public:
 property System::Windows::Media::Brush ^ OpacityMask { System::Windows::Media::Brush ^ get(); void set(System::Windows::Media::Brush ^ value); };

public System.Windows.Media.Brush OpacityMask { get; set; }

member this.OpacityMask : System.Windows.Media.Brush with get, set

Public Property OpacityMask As Brush

Property Value

Brush

The brush to use for opacity masking.

Examples

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>

Remarks

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 Painting with Solid Colors and Gradients Overview.

Dependency Property Information

Identifier field	OpacityMaskProperty
Metadata properties set to true	None

See also

• Opacity