An application sends the WM_MDIICONARRANGE message to a multiple document interface (MDI) client window to arrange all minimized MDI child windows. It does not affect child windows that are not minimized.
WM_MDIICONARRANGE
wParam = 0; // not used; must be zero
lParam = 0; // not used; must be zero
This message has no parameters.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winuser.h.
Multiple Document Interface Overview, Multiple Document Interface Messages, WM_MDICASCADE, WM_MDITILE