CompositionMaskBrush 类

定义

命名空间:: Windows.UI.Composition

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

编辑

使用应用于它的不透明度掩码的 CompositionBrush 绘制 SpriteVisual。不透明度掩码的来源可以是 CompositionColorBrush、CompositionLinearGradientBrush、CompositionSurfaceBrush、CompositionEffectBrush 或 CompositionNineGridBrush 类型的 CompositionBrush。不透明度掩码必须指定为 CompositionSurfaceBrush。

public ref class CompositionMaskBrush sealed : CompositionBrush

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 196608)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class CompositionMaskBrush final : CompositionBrush

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 196608)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class CompositionMaskBrush : CompositionBrush

Public NotInheritable Class CompositionMaskBrush
Inherits CompositionBrush

继承: Object Platform::Object IInspectable CompositionObject CompositionBrush CompositionMaskBrush

属性: ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows 要求

要求	说明
设备系列	Windows 10 Anniversary Edition (在 10.0.14393.0 中引入)
API contract	Windows.Foundation.UniversalApiContract (在 v3.0 中引入)

示例

完整示例：从图像文件应用掩码

以下示例演示如何创建 CompositionMaskBrush 端到端，包括加载掩码图像。将 PNG 与 alpha 通道一起使用：掩码的完全不透明区域使源可见，完全透明区域隐藏它，中间 alpha 值会产生部分透明度。掩码的 RGB 颜色值不控制不透明度;不透明的黑白图像不会创建透明掩码。

// Get the Compositor from a XAML element
Compositor compositor = ElementCompositionPreview.GetElementVisual(myElement).Compositor;

// Create the mask brush
CompositionMaskBrush maskBrush = compositor.CreateMaskBrush();

// Create the source (the content to be masked)
CompositionColorBrush colorBrush = compositor.CreateColorBrush(Colors.Blue);
maskBrush.Source = colorBrush;

// Load a mask image and create a surface brush from it
// The PNG's alpha channel defines the mask (opaque = visible, transparent = hidden)
LoadedImageSurface maskSurface = LoadedImageSurface.StartLoadFromUri(new Uri("ms-appx:///Assets/CircleMask.png"));
CompositionSurfaceBrush maskSurfaceBrush = compositor.CreateSurfaceBrush(maskSurface);
maskBrush.Mask = maskSurfaceBrush;

// Apply to a SpriteVisual and add it to the XAML tree
SpriteVisual visual = compositor.CreateSpriteVisual();
visual.Brush = maskBrush;
visual.Size = new System.Numerics.Vector2(200, 200);
ElementCompositionPreview.SetElementChildVisual(myElement, visual);

将星形掩码应用于图像

以下示例演示了使用 CompositionMaskBrush 的各种方法。每个示例都接收预先创建的 ICompositionSurface 实例。可以使用 LoadedImageSurface 创建这些图面，如上面的示例所示，也可以通过 Win2D 创建这些图面。

private SpriteVisual CreateCircleImage(ICompositionSurface myImageSurface, ICompositionSurface myStarMaskSurface) 
{ 
  // Create SurfaceBrush with image surface and specify stretch and alignment 
  CompositionSurfaceBrush imageBrush = _compositor.CreateSurfaceBrush(myImageSurface); 
  imageBrush.HorizontalAlignmentRatio = 0.5f; 
  imageBrush.VerticalAlignmentRatio = 0.5f; 
  imageBrush.Stretch = CompositionStretch.UniformToFill; 

  // Create surface brush with opacity mask surface and specify stretch and alignment 
  CompositionSurfaceBrush starMaskBrush = _compositor.CreateSurfaceBrush(myStarMaskSurface); 
  starMaskBrush.Stretch = CompositionStretch.Uniform; 

  // SpriteVisual to be painted with masked content 
  SpriteVisual imageVisual = _compositor.CreateSpriteVisual(); 
  imageVisual.Size = new Vector2(200, 200); 

  // Create MaskBrush 
  CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush(); 
  maskBrush.Source = imageBrush; // Set source to content that is to be masked 
  maskBrush.Mask = starMaskBrush; // Set mask to content that is the opacity mask 

  imageVisual.Brush = maskBrush; // Paint SpriteVisual with MaskBrush 

  return imageVisual;           
}

创建不透明度掩码以创建彩色开花效果的动画

private void CreateCircleMaskSprite(ICompositionSurface myCircleMaskSurface, ICompositionSurface myImageSurface)
{
  // SpriteVisual to be painted by MaskBrush
  _circleVisual = _compositor.CreateSpriteVisual();
  _circleVisual.Size = MyContainerGrid.RenderSize.ToVector2();

  // SurfaceBrush w/ image as MaskBrush.Source
  CompositionSurfaceBrush imageBrush = _compositor.CreateSurfaceBrush(myImageSurface);
  imageBrush.Stretch = CompositionStretch.UniformToFill;

  // SurfaceBrush w/ opacity mask surface as MaskBrush.Mask
  CompositionSurfaceBrush circleBrush = _compositor.CreateSurfaceBrush(myCircleMaskSurface);

  // Specify stretch and transform properties to scale and position brush for initial state
  circleBrush.Stretch = CompositionStretch.Uniform;
  circleBrush.CenterPoint = _circleVisual.Size / 2;
  circleBrush.Scale = new Vector2(0.5f);

  // Create MaskBrush
  CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush();
  maskBrush.Source = imageBrush;
  maskBrush.Mask = circleBrush;
  _circleVisual.Brush = maskBrush;

  // Set SpriteVisual as child of XAML Grid
  ElementCompositionPreview.SetElementChildVisual(MyContainerGrid, _circleVisual);
}

private void BloomAnimation()
{
  // Create KeyFrame Animation to target Scale transform on SurfaceBrush 
  Vector2KeyFrameAnimation scaleAnimation = _compositor.CreateVector2KeyFrameAnimation();
  scaleAnimation.InsertKeyFrame(1.0f, new Vector2(2));
  scaleAnimation.Duration = TimeSpan.FromMilliseconds(500);

  var maskBrush = (CompositionMaskBrush)_circleVisual.Brush;
  var surfaceBrush = (CompositionSurfaceBrush) maskBrush.Mask;

  // Animate the Scale on the circle opacity mask
  surfaceBrush.StartAnimation("Scale", scaleAnimation);      
}

对圆角矩形使用 NineGridBrush 掩码

private SpriteVisual CreateMaskedRoundedRectVisual(ICompositionSurface myRoundedRectMaskSurface)
{
  // ColorBrush to be set as MaskBrush.Source
  CompositionColorBrush colorBrush = _compositor.CreateColorBrush(Colors.Blue);

  // SurfaceBrush w/ opacity mask surface
  CompositionSurfaceBrush roundedRectBrush = _compositor.CreateSurfaceBrush(myRoundedRectMaskSurface);
  roundedRectBrush.Stretch = CompositionStretch.Fill; // stretch for center of nine-grid

  // NineGridBrush w/ insets on opacity mask surface
  CompositionNineGridBrush ninegridBrush = _compositor.CreateNineGridBrush();
  ninegridBrush.Source = roundedRectBrush;
  ninegridBrush.SetInsets(_cornerRadius); // the radius, in pixels, of the corner as specified on my opacity mask surface 

  // Create MaskBrush
  CompositionMaskBrush maskBrush = _compositor.CreateMaskBrush();
  maskBrush.Source = colorBrush;
  maskBrush.Mask = ninegridBrush;

  // Paint SpriteVisual with MaskBrush
  SpriteVisual sprite = _compositor.CreateSpriteVisual();
  sprite.Size = new Vector2(300, 200);
  sprite.Brush = maskBrush;
  return sprite;

}

注解

CompositionMaskBrush 不能设置为 CompositionEffectBrush 的源参数。如果要将 IGraphicsEffect 应用于屏蔽的内容，请改用 CompositionEffectBrush 和复合效果。

属性

名称	说明
Comment	要与 CompositionObject 关联的字符串。 (继承自 CompositionObject)
Compositor	用于创建此 CompositionObject 的 Compositor。 (继承自 CompositionObject)
Dispatcher	CompositionObject 的调度程序。 (继承自 CompositionObject)
DispatcherQueue	获取 CompostionObject 的 DispatcherQueue 。 (继承自 CompositionObject)
ImplicitAnimations	附加到此对象的隐式动画的集合。 (继承自 CompositionObject)
Mask	包含要屏蔽源画笔内容的不透明度掩码的画笔。可以是 CompositionSurfaceBrush 或 CompositionNineGridBrush 类型。
Properties	与 CompositionObject 关联的属性的集合。 (继承自 CompositionObject)
Source	一个画笔，其内容将由不透明度掩码屏蔽。可以是 CompositionSurfaceBrush、CompositionColorBrush 或 CompositionNineGridBrush 类型。

方法

名称	说明
Close()	关闭 CompositionObject 并释放系统资源。 (继承自 CompositionObject)
Dispose()	执行与释放、释放或重置非托管资源关联的应用程序定义任务。 (继承自 CompositionObject)
PopulatePropertyInfo(String, AnimationPropertyInfo)	定义可以进行动画处理的属性。 (继承自 CompositionObject)
StartAnimation(String, CompositionAnimation, AnimationController)	将动画与对象的指定属性连接，并启动动画。 (继承自 CompositionObject)
StartAnimation(String, CompositionAnimation)	将动画与对象的指定属性连接，并启动动画。 (继承自 CompositionObject)
StartAnimationGroup(ICompositionAnimationBase)	启动动画组。 CompositionObject 上的 StartAnimationGroup 方法允许启动 CompositionAnimationGroup。组中的所有动画将在对象上同时启动。 (继承自 CompositionObject)
StopAnimation(String)	断开与指定属性的动画的连接，并停止动画。 (继承自 CompositionObject)
StopAnimationGroup(ICompositionAnimationBase)	停止动画组。 (继承自 CompositionObject)
TryGetAnimationController(String)	返回指定属性上运行的动画的 AnimationController。 (继承自 CompositionObject)

适用于

另请参阅

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