CachingHint Enum
Definition
Important
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Specifies whether to cache tiled brush objects.
public enum class CachingHintpublic enum CachingHinttype CachingHint = Public Enum CachingHint- Inheritance
Fields
| Name | Value | Description |
|---|---|---|
| Unspecified | 0 | No caching hints are specified. |
| Cache | 1 | Cache the tiled brush objects in an off-screen buffer, using the caching hints specified by the RenderOptions settings. |
Examples
The following example shows how to use the caching hint option for a DrawingBrush.
DrawingBrush drawingBrush = new DrawingBrush();
// Set the caching hint option for the brush.
RenderOptions.SetCachingHint(drawingBrush, CachingHint.Cache);
// Set the minimum and maximum relative sizes for regenerating the tiled brush.
// The tiled brush will be regenerated and re-cached when its size is
// 0.5x or 2x of the current cached size.
RenderOptions.SetCacheInvalidationThresholdMinimum(drawingBrush, 0.5);
RenderOptions.SetCacheInvalidationThresholdMaximum(drawingBrush, 2.0);
Dim drawingBrush As New DrawingBrush()
' Set the caching hint option for the brush.
RenderOptions.SetCachingHint(drawingBrush, CachingHint.Cache)
' Set the minimum and maximum relative sizes for regenerating the tiled brush.
' The tiled brush will be regenerated and re-cached when its size is
' 0.5x or 2x of the current cached size.
RenderOptions.SetCacheInvalidationThresholdMinimum(drawingBrush, 0.5)
RenderOptions.SetCacheInvalidationThresholdMaximum(drawingBrush, 2.0)
Remarks
By default, WPF does not cache the rendered contents of DrawingBrush and VisualBrush objects. In static scenarios where neither the contents nor the use of the brush in the scene is changing, not caching provides a benefit because it conserves video memory. When a brush with static content is used in a non-static way, the default behavior of WPF is to re-render the entire content of the brush every frame, even though the content is unchanging. For example, this will happen when a static DrawingBrush or VisualBrush is mapped to the surface of a rotating 3D object. Re-rendering the static content can have a negative impact on performance.
By setting the CachingHint attached property on the brush to Cache, you can increase performance by using cached versions of the tiled brush objects.
The CacheInvalidationThresholdMinimum and CacheInvalidationThresholdMaximum property values are relative size values that determine when the TileBrush object should be regenerated due to changes in scale. For example, by setting the CacheInvalidationThresholdMaximum property to 2.0, the cache for the TileBrush only needs to be regenerated when its size exceeds twice the size of the current cache.
