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tushe 2002-05-18
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CWindow::InvalidateRect
This method invalidates the client area within the specified rectangle.
BOOL InvalidateRect(
LPCRECT lpRect,
BOOL bErase = TRUE);
Parameters
lpRect
Long pointer to a RECT structure that contains the client coordinates of the rectangle to be added to the update region. If this parameter is NULL, the entire client area is added to the update region.
bErase
Boolean that specifies whether the background within the update region is to be erased when the update region is processed. If this parameter is TRUE, the background is erased when the BeginPaint function is called. If this parameter is FALSE, the background remains unchanged.
Return Values
Nonzero indicates success. Zero indicates failure.
To get extended error information, call GetLastError.
Remarks
The invalidated areas accumulate in the update region until the region is processed when the next WM_PAINT message occurs or until the region is validated by using the ValidateRect function.
The system sends a WM_PAINT message to a window whenever its update region is not empty and there are no other messages in the application queue for that window.
If the bErase parameter is TRUE for any part of the update region, the background is erased in the entire region, not just in the specified part.
Requirements
Windows CE versions: 2.0 and later
Header file: Declared in Atlwin.h
Platform: H/PC Pro, Palm-size PC, Pocket PC
See Also
This method invalidates the client area within the specified rectangle.
BOOL InvalidateRect(
LPCRECT lpRect,
BOOL bErase = TRUE);
Parameters
lpRect
Long pointer to a RECT structure that contains the client coordinates of the rectangle to be added to the update region. If this parameter is NULL, the entire client area is added to the update region.
bErase
Boolean that specifies whether the background within the update region is to be erased when the update region is processed. If this parameter is TRUE, the background is erased when the BeginPaint function is called. If this parameter is FALSE, the background remains unchanged.
Return Values
Nonzero indicates success. Zero indicates failure.
To get extended error information, call GetLastError.
Remarks
The invalidated areas accumulate in the update region until the region is processed when the next WM_PAINT message occurs or until the region is validated by using the ValidateRect function.
The system sends a WM_PAINT message to a window whenever its update region is not empty and there are no other messages in the application queue for that window.
If the bErase parameter is TRUE for any part of the update region, the background is erased in the entire region, not just in the specified part.
Requirements
Windows CE versions: 2.0 and later
Header file: Declared in Atlwin.h
Platform: H/PC Pro, Palm-size PC, Pocket PC
See Also
