WoW-Info — информационный World of Warcraft портал

The CreateRoundRectRgn function creates a rectangular
region with rounded corners
}

procedure TForm1.FormCreate(Sender: TObject);
var
rgn: HRGN;
begin
Form1.Borderstyle := bsNone;
rgn := CreateRoundRectRgn(0,// x-coordinate of the region's upper-left corner
0, // y-coordinate of the region's upper-left corner
ClientWidth, // x-coordinate of the region's lower-right corner
ClientHeight, // y-coordinate of the region's lower-right corner
40, // height of ellipse for rounded corners
40); // width of ellipse for rounded corners
SetWindowRgn(Handle, rgn, True);
end

{ The CreatePolygonRgn function creates a polygonal region. }

procedure TForm1.FormCreate(Sender: TObject);
const
C = 20;
var
Points: array [0..7] of TPoint;
h, w: Integer;
begin
h := Form1.Height;
w := Form1.Width;
Points[0].X := C; Points[0].Y := 0;
Points[1].X := 0; Points[1].Y := C;
Points[2].X := 0; Points[2].Y := h - c;
Points[3].X := C; Points[3].Y := h;

Points[4].X := w - c; Points[4].Y := h;
Points[5].X := w; Points[5].Y := h - c;

Points[6].X := w; Points[6].Y := C;
Points[7].X := w - C; Points[7].Y := 0;

SetWindowRgn(Form1.Handle, CreatePolygonRgn(Points, 8, WINDING), True);
end;