ExcludeUpdateRgn

2.x

int ExcludeUpdateRgn(hdc, hwnd)
HDC hdc;	/* handle of device context	*/
HWND hwnd;	/* handle of window, */

The ExcludeUpdateRgn function prevents drawing within invalid areas of a window by excluding an updated region in the window from a clipping region.

Parameters

hdc

Identifies the device context associated with the clipping region.

hwnd

Identifies the window to be updated.

Return Value

The return value is SIMPLEREGION (region has no overlapping borders), COMPLEXREGION (region has overlapping borders), or NULLREGION (region is empty), if the function is successful. Otherwise, the return value is ERROR (no region is created).