The MCIWNDM_GETFILENAME message retrieves the filename currently used by an MCI device. You can send this message explicitly or by using the MCIWndGetFileName macro.
MCIWNDM_GETFILENAME
wParam = (WPARAM) (UINT) len;
lParam = (LPARAM) (LPVOID) lp;
Returns zero if successful or 1 otherwise.
If the null-terminated string containing the filename is longer than the buffer, MCIWnd truncates the filename.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Unicode: Defined as Unicode and ANSI messages.
MCIWnd Window Class Overview, MCIWnd Messages, MCIWndGetFileName