DeviceSubClass Property

项目
09/21/2010

The DeviceSubClass property returns the value of the bDeviceSubClass field of the device descriptor, as defined in section 9.6.1 of the USB 2.0 specification. This property is read/write.

This property is read/write.

Syntax

HRESULT put_DeviceSubClass(
  [in]           BYTE bDeviceSubClass
);

HRESULT get_DeviceSubClass(
  [out, retval]  BYTE *pbDeviceSubClass
);

Property Value

The new device subclass.

Error Codes

DeviceSubClass returns an HRESULT value.

Remarks

The following C++ code example shows how to set and get the DeviceSubClass property.

HRESULT CLoopBackDevice::SetDeviceSubClass(ISoftUSBDevice *piDevice)
{
HRESULT hr = S_OK;
BYTE         bDeviceSubClass= 0;
BYTE         bNewDeviceSubClass = 0xff; //Vendor specific sub class 

 if (NULL == piDevice)
{
 hr = E_POINTER;
 goto Exit;
}

 hr = piDevice->get_DeviceSubClass(&bDeviceSubClass);
 if(FAILED(hr))
 goto Exit;

 if (bDeviceSubClass != bNewDeviceSubClass)
{
 hr = piDevice->put_DeviceClass(bNewDeviceSubClass);
 if(FAILED(hr))
 goto Exit;
}
Exit:
 return hr;
}

Requirements

Header

SoftUSBif.h

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Build date: 9/21/2010

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