StrokeCollection.Erase Method (Rect)
Replaces all strokes that are clipped by the specified rectangle with new strokes that do not enter the bounds of the specified rectangle.
Assembly: PresentationCore (in PresentationCore.dll)
The StrokeCollection might contain new strokes after the Erase method is called. For example, if the specified area is through the middle of a Stroke, the erase method removes that Stroke and creates two new strokes. All strokes that are entirely inside the specified rectangle are removed.