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WIDM_CLOSE (Compact 2013)

  • Article

3/26/2014

This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform input driver to close a specified device instance previously opened with WIDM_OPEN.

Parameters

  • uDeviceId
    Device identifier - 0, 1, 2, and so on - for the target device.
  • uMsg
    Specifies this message.
  • dwUser
    Specifies a device instance identifier.
  • dwParam1
    Not used.
  • dwParam2
    Not used.

Return Values

MMSYSERR_NOERROR indicates success. Otherwise, the driver returns one of the MMSYSERR or WAVERR error values declared in the Mmsystem.h header file.

Remarks

The ACM (Waveapi.dll) sends the WIDM_CLOSE message by calling the audio driver's (Wavedev.dll) WAV_IOControl entry point through the DeviceIoControl function.

If the driver has not filled and returned all the buffers received with WIDM_ADDBUFFER messages, it does not close the instance. Instead, it returns WAVERR_STILLPLAYING.

After the driver closes the device instance, it sends a WIM_CLOSE callback message to the ACM.

Requirements

Header

mmddk.h

See Also

Reference

Waveform Input Driver Messages
WAV_IOControl
MMDRV_MESSAGE_PARAMS