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MXDM_OPEN (Compact 2013)

  • Article

3/26/2014

This message requests a user-mode mixer driver to open an instance of the specified device.

Syntax

typedef struct {
  DWORD uDeviceId;
  UINT uMsg;
  DWORD dwUser;
  DWORD lParam1;
  DWORD lParam2;
} MXDM_OPEN;

Members

  • uDeviceId
    Device identifier for the target device. It can be 0, 1, 2, and so on.
  • uMsg
    Equals MXDM_OPEN.
  • dwUser
    Address of location into which the driver places the instance identifier.
  • lParam2
    Contains flag values. This is always equal to CALLBACK_FUNCTION.

Return Value

Returns MMSYSERR_NOERROR if the operation is successful. Otherwise, it returns one of the MMSYSERR or MIXERR error codes defined in Mmsystem.h. See mixerOpen return values in the Win32 Software Development Kit (SDK).

Remarks

A client sends the MXDM_OPEN message by calling the user-mode driver's mxmdMessage entry point, passing the specified parameters.

Often, creating a driver instance simply entails creating an instance-specific data structure. The instance identifier can be a handle to this structure.

Requirements

Header

mmddk.h

See Also

Reference

Audio Mixer Messages