Window.InvalidateShadowMBS

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	Window	MBS MacOSX Plugin	8.7	✅ Yes	❌ No	❌ No	❌ No	Desktop only

This method causes a window's shadow to be recalculated.

InvalidateShadowMBS is not typically used by applications. However, it may be useful for applications with customized window frames that change shape dynamically; in this case, after the application has drawn the new window shape, the window shadow must be recalculated to follow the new window shape.

This method causes the window shadow to be immediately recalculated and redrawn based on the current contents of the window's back buffer. For best performance and visual appearance, you should follow these steps when invalidating a window shadow: disable updates with DisableScreenUpdatesMBS, draw, flush, invalidate the shadow, and enable updates. For a compositing window, after invalidating any views that should be redrawn, you will need to explicitly draw and flush using HIWindowFlush, rather than waiting for the event loop to draw and flush the window, because you cannot disable updates or invalidate the window shadow if drawing is done via the event loop.