MIDIOPENDESC

This structure contains information needed by a MIDI input or MIDI output device driver when devices are opened with a MODM_OPEN or MIDM_OPEN message.

typedef struct midiopendesc_tag {

HMIDI hMidi;

DWORD dwCallback;

DWORD dwInstance;

} MIDIOPENDESC;

Fields

The MIDIOPENDESC structure has the following fields:

hMidi

Specifies the client's handle to the device, assigned by MMSYSTEM. Use this handle when notifying the client with the DriverCallback function.

dwCallback

Specifies either the address of a callback function, a window handle, or a task handle, depending on the flags specified in the dwParam2 parameter of the MODM_OPEN or MIDM_OPEN message. If this field contains a handle it is contained in the low-order word. The driver uses this information to notify the client using the DriverCallback function.

dwInstance

Specifies a DWORD of instance information for the client. This instance information is returned to the client whenever the driver notifies the client using the DriverCallback function.

See Also

MODM_OPEN, MIDM_OPEN