| int ExcludeUpdateRgn(hdc, hwnd) | |||||
| HDC hdc; | /* handle of device context | */ | |||
| HWND hwnd; | /* handle of window | */ | |||
This function prevents drawing within invalid areas of a window by excluding an updated region in the window from a clipping region.
hdc
Identifies the device context associated with the clipping region.
hwnd
Identifies the window being updated.
The return value is the type of excluded region. It can be any one of the following values:
| Value | Meaning |
| COMPLEXREGION | The region has overlapping borders. |
| ERROR | No region was created. |
| NULLREGION | The region is empty. |
| SIMPLEREGION | The region has no overlapping borders. |
ValidateRgn