CompositionRadialGradientBrush Class

Definition

Namespace:

Microsoft.UI.Composition

Represents a brush that paints an area with a radial gradient.

public ref class CompositionRadialGradientBrush sealed : CompositionGradientBrush

/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
/// [Windows.Foundation.Metadata.ContractVersion(Microsoft.Foundation.WindowsAppSDKContract, 65536)]
class CompositionRadialGradientBrush final : CompositionGradientBrush

[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
[Windows.Foundation.Metadata.ContractVersion(typeof(Microsoft.Foundation.WindowsAppSDKContract), 65536)]
public sealed class CompositionRadialGradientBrush : CompositionGradientBrush

Public NotInheritable Class CompositionRadialGradientBrush
Inherits CompositionGradientBrush

Inheritance

Object Platform::Object IInspectable CompositionObject CompositionBrush CompositionGradientBrush CompositionRadialGradientBrush

Attributes

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Examples

Create a radial gradient brush

This example shows how to create a radial gradient brush, add 2 color stops, and paint a SpriteVisual with it.

// Create radial gradient brush.
CompositionRadialGradientBrush RGBrush = compositor.CreateRadialGradientBrush();

// Create the color stops by defining the offset and color.
CompositionColorGradientStop ColorStop1 = compositor.CreateColorGradientStop();
ColorStop1.Offset = 0;
ColorStop1.Color = Colors.Blue;
CompositionColorGradientStop ColorStop2 = compositor.CreateColorGradientStop();
ColorStop2.Offset = 1;
ColorStop2.Color = Colors.Yellow;

// Add the color stops to brush's ColorStops collection.
RGBrush.ColorStops.Add(ColorStop1);
RGBrush.ColorStops.Add(ColorStop2);

// Create a sprite visual and paint it with the radial gradient brush.
var visual = compositor.CreateSpriteVisual();
visual.Size = new Vector2(120, 120);
visual.Brush = RGBrush;

You can also condense the steps to create and add the color stops using this shorter syntax:

RGBrush.ColorStops.Add(compositor.CreateColorGradientStop(0, Colors.Blue));
RGBrush.ColorStops.Add(compositor.CreateColorGradientStop(1, Colors.Yellow));

Animate a radial gradient brush

This example shows how to animate the color of the first gradient stop of a radial gradient brush.

private SpriteVisual GetRadialGradientVisualWithAnimation(Vector2 size,
                                                          Vector2 gradientOriginOffset,
                                                          Vector2 ellipseCenter,
                                                          Vector2 ellipseRadius)
{
    // Create radial gradient brush.
    var gradientBrush = compositor.CreateRadialGradientBrush();
    gradientBrush.GradientOriginOffset = gradientOriginOffset;
    gradientBrush.EllipseCenter = ellipseCenter;
    gradientBrush.EllipseRadius = ellipseRadius;

    // Add the color stops. The first color stop needs a name so you can refer to it later.
    CompositionColorGradientStop ColorStop1 = compositor.CreateColorGradientStop(0, Colors.Blue);
    gradientBrush.ColorStops.Add(ColorStop1);
    gradientBrush.ColorStops.Add(compositor.CreateColorGradientStop(1, Colors.Yellow));

    // Set up animation for ColorStop1's color.
    var colorAnimation = compositor.CreateColorKeyFrameAnimation();
    colorAnimation.InsertKeyFrame(0.0f, Colors.Blue);
    colorAnimation.InsertKeyFrame(0.5f, Colors.LightBlue);
    colorAnimation.InsertKeyFrame(0.75f, Colors.Navy);
    colorAnimation.InsertKeyFrame(1.0f, Colors.Blue);
    colorAnimation.Duration = TimeSpan.FromSeconds(20);
    colorAnimation.IterationBehavior = AnimationIterationBehavior.Forever;
    ColorStop1.StartAnimation("Color", colorAnimation);

    // SpriteVisual to be painted with gradated content.
    var gradientVisual = compositor.CreateSpriteVisual();
    gradientVisual.Size = size;
    // Set brush on the SpriteVisual.
    gradientVisual.Brush = gradientBrush;

    return gradientVisual;
}

Remarks

This brush paints a SpriteVisual with a radial gradient.

The gradient is drawn within an ellipse that is defined by the EllipseCenter and EllipseRadius properties. Colors for the gradient start at the center of the ellipse and end at the radius.

The colors for the radial gradient are defined by color stops. Each color stop specifies a color and a location along the gradient.

Properties

AnchorPoint	Gets or sets the point on the brush to be positioned at the brush's offset. (Inherited from CompositionGradientBrush)
CenterPoint	Gets or sets the point about which the brush is rotated and scaled. (Inherited from CompositionGradientBrush)
ColorStops	Gets the brush's gradient stops. (Inherited from CompositionGradientBrush)
Comment	A string to associate with the CompositionObject. (Inherited from CompositionObject)
Compositor	The Compositor used to create this CompositionObject. (Inherited from CompositionObject)
DispatcherQueue	Gets the DispatcherQueue for the CompositionObject. (Inherited from CompositionObject)
EllipseCenter	Gets or sets the two-dimensional coordinates of the center of the ellipse that contains the gradient.
EllipseRadius	Gets or sets the radii of the ellipse that contains the gradient.
ExtendMode	Gets or sets a value that specifies how to draw the gradient outside the brush's gradient vector or space. (Inherited from CompositionGradientBrush)
GradientOriginOffset	Gets or sets the two-dimensional coordinates of the origin of the gradient.
ImplicitAnimations	The collection of implicit animations attached to this object. (Inherited from CompositionObject)
InterpolationSpace	Gets or sets a value that specifies how the gradient's colors are interpolated. (Inherited from CompositionGradientBrush)
MappingMode	Gets or sets a value that indicates whether the gradient brush's positioning coordinates (StartPoint, EndPoint) are absolute or relative to the output area. (Inherited from CompositionGradientBrush)
Offset	Gets or sets the offset of the brush relative to the object being painted. (Inherited from CompositionGradientBrush)
Properties	The collection of properties associated with the CompositionObject. (Inherited from CompositionObject)
RotationAngle	Gets or sets the rotation angle of the brush in radians. (Inherited from CompositionGradientBrush)
RotationAngleInDegrees	Gets or sets the rotation angle of the brush in degrees. (Inherited from CompositionGradientBrush)
Scale	Gets or sets the scale to apply to the brush. (Inherited from CompositionGradientBrush)
TransformMatrix	Gets or sets the matrix of transforms to apply to the brush. (Inherited from CompositionGradientBrush)

Methods

Close()	Closes the CompositionObject and releases system resources. (Inherited from CompositionObject)
Dispose()	Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. (Inherited from CompositionObject)
PopulatePropertyInfo(String, AnimationPropertyInfo)	Defines a property that can be animated. (Inherited from CompositionObject)
StartAnimation(String, CompositionAnimation, AnimationController)	Connects an animation with the specified property of the object and starts the animation. (Inherited from CompositionObject)
StartAnimation(String, CompositionAnimation)	Connects an animation with the specified property of the object and starts the animation. (Inherited from CompositionObject)
StartAnimationGroup(ICompositionAnimationBase)	Starts an animation group. The StartAnimationGroup method on CompositionObject lets you start CompositionAnimationGroup. All the animations in the group will be started at the same time on the object. (Inherited from CompositionObject)
StopAnimation(String)	Disconnects an animation from the specified property and stops the animation. (Inherited from CompositionObject)
StopAnimationGroup(ICompositionAnimationBase)	Stops an animation group. (Inherited from CompositionObject)
TryGetAnimationController(String)	Returns an AnimationController for the animation running on the specified property. (Inherited from CompositionObject)

See also

• Brush