ValidateRect

This function validates the client area within a rectangle by removing the rectangle from the update region of the specified window.

At a Glance

Header file:	Winuser.h
Windows CE versions:	1.0 and later

Syntax

BOOL ValidateRect( HWND hWnd, const RECT *lpRect );

Parameters

hWnd

Handle to the window whose update region is to be modified. If this parameter is NULL, the system invalidates and redraws all windows and sends the WM_ERASEBKGND and WM_NCPAINT messages to the window procedure before the function returns.

lpRect

Long pointer to a RECT structure that contains the client coordinates of the rectangle to be removed from the update region. If this parameter is NULL, the entire client area is removed.

Return Values

Nonzero indicates success. Zero indicates failure.

Windows NT: To get extended error information, call GetLastError.

Windows CE Remarks

Passing in a NULL value for the hWnd parameter is not supported.

Remarks

The BeginPaint function automatically validates the entire client area. Neither the ValidateRect nor ValidateRgn function should be called if a portion of the update region must be validated before the next WM_PAINT message is generated.

The system continues to generate WM_PAINT messages until the current update region is validated.