DRV_QUERYMAPPABLE function
The DRV_QUERYMAPPABLE message queries for whether the specified device can be used by a mapper.
Syntax
DWORD xxxMessage(
UINT uDeviceID,
UINT uMsg,
DWORD_PTR dwParam1,
DWORD_PTR dwParam2
);
Parameters
uDeviceID
Specifies the ID of the target device.uMsg
Caller sets this parameter to DRV_QUERYMAPPABLE when it calls xxxMessage to process this device message.dwParam1
Unused. Set this parameter to zero.dwParam2
Unused. Set this parameter to zero.
Return value
The xxxMessage function returns MMSYSERR_NOERROR if the device is mappable. Otherwise, it returns an appropriate error code.
Remarks
This message is valid only for the waveInMessage, waveOutMessage, midiInMessage, midiOutMessage, mixerMessage and auxOutMessage functions. The system intercepts this message and returns the appropriate value without sending the message to the device driver. For general information about system-intercepted xxxMessage functions, see System-Intercepted Device Messages.
When an application program opens a mapper instead of a specific audio device, the system inserts a mapper between the application and the available devices. The mapper selects an appropriate device by mapping the application's requirements to one of the available devices. For more information about mappers, see the Microsoft Windows SDK documentation.
Requirements
Target platform |
Desktop |
Version |
Supported in Microsoft Windows Me/98 and Windows 2000 and later operating systems. |
Header |
Mmddk.h (include Mmddk.h) |