CompositionRadialGradientBrush 类

定义

public ref class CompositionRadialGradientBrush sealed : CompositionGradientBrush

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

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

继承

Object Platform::Object IInspectable CompositionObject CompositionBrush CompositionGradientBrush CompositionRadialGradientBrush

属性

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

示例

创建径向渐变画笔

此示例演示如何创建径向渐变画笔、添加 2 个颜色停止点，以及如何使用它绘制 SpriteVisual。

// 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;

还可以使用以下较短的语法压缩创建和添加颜色停止点的步骤：

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

对径向渐变画笔进行动画处理

此示例演示如何对径向渐变画笔的第一个渐变停止点的颜色进行动画处理。

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;
}

注解

此画笔使用径向渐变绘制 SpriteVisual 。

渐变是在由 EllipseCenter 和 EllipseRadius 属性定义的椭圆内绘制的。 渐变的颜色开始于椭圆的中心之处，结束于半径之处。

径向渐变的颜色由颜色停止点定义。 每个颜色停止点指定一种颜色以及沿渐变的位置。

属性

方法

适用于

另请参阅

• Brush