次の方法で共有

WODM_GETVOLUME (Compact 2013)

  • [アーティクル]

3/26/2014

This message is used in an MMDRV_MESSAGE_PARAMS structure passed to the WAV_IOControl function to request a waveform output driver to return the current volume level setting for the specified device.

Parameters

  • uDeviceId
    Device identifier - 0, 1, 2, and so on - for the device.
  • uMsg
    Specifies this structure.
  • dwUser
    Specifies a device instance identifier.
  • dwParam1
    Pointer to a DWORD location to receive the volume setting.
  • 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 WAVEFORM API MANAGER sends this message by calling the audio driver's WAV_IOControl entry point through the DeviceIoControl function. Support for this message by drivers is optional. However, if the driver supports WODM_SETVOLUME, it must support this message. The following table shows which bytes in dwParam1 indicate the volume settings for both stereo and monaural audio channels.

Channel

Portion of dwParam1 used

Left channel

Low WORD

Right channel

High WORD

Single channel

Low WORD

A value of 0 is silence, and a value of 0xFFFF is full volume.

Requirements

Header

mmddk.h

See Also

Reference

Waveform Output Driver Messages
WAV_IOControl
MMDRV_MESSAGE_PARAMS