An application sends a BM_SETSTYLE message to change the style of a button.
BM_SETSTYLE
wParam = (WPARAM) LOWORD(dwStyle); // style
lParam = MAKELPARAM(fRedraw, 0); // redraw flag
This message always returns zero.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Buttons Overview, Button Messages