'宣言 Protected Friend Overrides Function GetOverlayGeometry( _ ByVal scaledValue As Double, _ ByVal windowRect As Rect, _ ByVal viewport As Rect, _ Optional ByVal effectiveViewport As Object, _ Optional ByVal contentViewport As Object _ ) As Geometry
protected internal override Geometry GetOverlayGeometry( double scaledValue, Rect windowRect, Rect viewport, object effectiveViewport, object contentViewport )