ExcludeUpdateRgn function

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

Syntax


int ExcludeUpdateRgn(
  _In_ HDC  hDC,
  _In_ HWND hWnd
);

Parameters

hDC [in]

Handle to the device context associated with the clipping region.

hWnd [in]

Handle to the window to update.

Return value

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

ValueMeaning
COMPLEXREGIONRegion consists of more than one rectangle.
ERRORAn error occurred.
NULLREGIONRegion is empty.
SIMPLEREGIONRegion is a single rectangle.

 

Requirements

Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]

Header

Winuser.h (include Windows.h)

Library

User32.lib

DLL

User32.dll

See also

Painting and Drawing Overview
Painting and Drawing Functions
BeginPaint
GetUpdateRect
GetUpdateRgn
UpdateWindow

 

 

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