Represents the callback method that specifies parts of the visual tree to omit from hit test processing
Assembly: PresentationCore (in PresentationCore.dll)
type HitTestFilterCallback = delegate of potentialHitTestTarget:DependencyObject -> HitTestFilterBehavior
- Type: System.Windows.DependencyObject
The visual to hit test.
The hit test filter callback method is invoked for all the visual objects that map to the hit test criteria, starting from the visual you specify and descending through its branch of the visual tree. However, you may want to ignore certain branches of the visual tree that you are not interested in processing in your hit test results callback function. The return value of the hit test filter callback function determines what type of action the enumeration of the visual objects should take. For example, if you return the value, ContinueSkipSelfAndChildren, you can remove the current visual object and its descendants from the hit test results enumeration. This means that the hit test results callback method will not see these objects in its enumeration.
Pruning the visual tree of objects decreases the amount of processing during the hit test results enumeration pass.
The following example shows how to invoke HitTest by using a value. The corresponding hit test callback method is also defined.
The following example shows how to return a HitTestFilterBehavior value from a hit test filter callback method.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2