MODM_UNPREPARE - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// mmddk.h
DWORD modMessage(
UINT uDeviceID,
UINT uMsg,
DWORD_PTR dwUser,
DWORD_PTR dwParam1,
DWORD_PTR dwParam2
);
View the official Windows hardware development documentationNo description available.
WINMM sends the MODM_UNPREPARE message to the modMessage function of a MIDI output driver to clean up the memory segment that was configured by MODM_PREPARE.
uDeviceID Specifies the ID of the target device. Device IDs are sequential and have an initial value of zero and a final value that is equal to one less than the number of devices that the driver supports.
uMsg WINMM sets this parameter to MODM_UNPREPAE when it calls modMessage to process this message.
dwUser Use this parameter to return instance data to the driver. Drivers that support multiple clients can use this instance data to track the client that is associated with the message.
dwParam1 Specifies a far pointer to a MIDIHDR structure that identifies the data block.
dwParam2 Specifies the size of the MIDIHDR structure.
The modMEssage function returns MMSYSERR_NOERROR if the operation is successful. Otherwise, it returns MMSYSERR_NOTENABLED to indicate that the driver failed to load or initialize.
Driver support for this message is optional. If a driver supports the MODM_PREPARE message, it must also support MODM_UNPREPARE.
The default response for this message is to return MMSYSERR_NOTSUPPORTED. In this case, Mmsystem.dll cleans up the preparation that was previously done on the memory block. If a driver performs the PREPARE operation, it must clean up the preparation and reset the MHDR_PREPARED flag in the dwFlags field of the MIDIHDR structure.
| Target platform | Desktop |
| Version | Available in Windows XP and later Windows operating systems. |
| Header | Mmddk.h (include Mmddk.h, Mmsystem.h, or Windows.h) |