MCIWNDM_NOTIFYSIZE  15JGEKV 

The MCIWNDM_NOTIFYSIZE message notifies the parent window of an application that the window size has changed.

MCIWNDM_NOTIFYSIZE

wParam = (WPARAM) (HWND) hwnd;

lParam = 0;

Parameters

hwnd

Handle of the MCIWnd window.

Remarks

You can enable notification of changes in the size of an MCIWnd window by specifying the MCIWNDF_NOTIFYSIZE window style.