ExcludeUpdateRgn  TDRZSP 

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

int ExcludeUpdateRgn(

    HDC hDC,

// handle to device context 

    HWND hWnd

// handle to window

   );

 

 

Parameters

hDC

Identifies the device context associated with the clipping region.

hWnd

Identifies the window to update.

 

Return Values

The return value specifies the complexity of the excluded region; it can be any one of the following values:

Value

Meaning

COMPLEXREGION

Region consists of more than one rectangle.

ERROR

An error occurred.

NULLREGION

Region is empty.

SIMPLEREGION

Region is a single rectangle.

 

See Also

BeginPaint, GetUpdateRect, GetUpdateRgn, UpdateWindow