void ValidateRgn(hWnd,hRgn)
This function validates the client area within the given region by removing the region from the current update region of the given window. If the hRgn parameter is NULL, the entire window is validated.
| Parameter | Type/Description |
| hWnd | HWND Identifies the window whose update region is to be modified. | |
| hRgn | HRGN Identifies a region that defines the area to be removed from the update region. |
None.
The given region must have been created previously by means of a region function (for more information, see Chapter 1, “Window Manager Interface Functions”). The region coordinates are assumed to be client coordinates.