SetRectRgn info Overview Group

The SetRectRgn function changes a region into a rectangular region with the specified coordinates.

BOOL SetRectRgn(

HRGN hrgn,	// handle of region
int nLeftRect,	// x-coordinate of upper-left corner of rectangle
int nTopRect,	// y-coordinate of upper-left corner of rectangle
int nRightRect,	// x-coordinate of lower-right corner of rectangle
int nBottomRect	// y-coordinate of lower-right corner of rectangle
);

Parameters

hrgn: Identifies the region.
nLeftRect: Specifies the x-coordinate of the upper-left corner of the rectangular region.
nTopRect: Specifies the y-coordinate of the upper-left corner of the rectangular region.
nRightRect: Specifies the x-coordinate of the lower-right corner of the rectangular region.
nBottomRect: Specifies the y-coordinate of the lower-right corner of the rectangular region.

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

The region does not include the lower and right boundaries of the rectangle.