| InvalidateRgn(IntPtr, IntPtr, Boolean) | Invalidates the client area within the specified region by adding it to the current update region of a window. The invalidated region, along with all other areas in the update region, is marked for painting when the next WM_Paint message occurs. |
| InvalidateRgn(SafeHandle, SafeHandle, Boolean) | Invalidates the client area within the specified region by adding it to the current update region of a window. The invalidated region, along with all other areas in the update region, is marked for painting when the next WM_Paint message occurs. |