This message is sent to an I/O procedure by mmioOpen to request that a file be opened or deleted.
LONG lParam1
Specifies a null-terminated string containing the name of the file to open.
LONG lParam2
Is not used.
The return value is zero if the operation is successful. Otherwise, the return value specifies an error value. Possible error returns are:
MMIOM_CANNOTOPEN
Specified file could not be opened.
MMIOM_OUTOFMEMORY
Not enough memory to perform operation.
The dwFlags field of the MMIOINFO structure contains option flags passed to the mmioOpen function. The lDiskOffset field of the MMIOINFO structure is initialized to zero. If this value is incorrect, then the I/O procedure must correct it.
If the caller passed a MMIOINFO structure to mmioOpen, the return value will be returned in the wErrorRet field.
mmioOpen, MMIOM_CLOSE