MIDM_UNPREPARE

Sent to a MIDI input device to clean up the preparation performed by the MIDM_PREPARE message.

The return value is an error code, or zero (MMSYSERR_NOERROR) if the operation is successful. Possible error codes are:

MMSYSERR_NOTENABLED

The driver failed to load or initialize.

DWORD dwParam1: Specifies a far pointer to MIDIHDR structure identifying the data buffer.
DWORD dwParam2: Specifies the size of the MIDIHDR structure.

Driver support for this message is optional. If a driver supports the MIDM_PREPARE message, then it must also support MIDM_UNPREPARE.

The default response for this message is to return MMSYSERR_NOTSUPPORTED. In this case, MMSYSTEM will clean up the preparation previously done on the memory buffer. If a driver performs the preparation itself, it must clean up the preparation and reset the MHDR_PREPARED flag in the dwFlags field of the MIDIHDR structure.

MIDM_UNPREPARE

See Also