Reserved Property

项目
09/21/2010

The Reserved property gets or sets the bReserved field of the device qualifier descriptor, as described in section 9.6.2 of the USB 2.0 specification.

This property is read/write.

Syntax

HRESULT put_Reserved(
  [in]   BYTE bReserved
);

HRESULT get_Reserved(
  [out]  BYTE *pbReserved
);

Property Value

The new reserved value for the device qualifier.

Error Codes

Reserved returns S_OK if the operation succeeds or E_POINTER if the pbReserved parameter is not a valid pointer.

This property can also return other standard COM return values.

Examples

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

HRESULT CLoopBackDevice::SetDeviceQualifierReserved(ISoftUSBDeviceQualifier *piQualifier)
{
HRESULT hr = S_OK;
BYTE         bReserved = 0;
BYTE         bNewReserved = 1;

if (NULL == piQualifier)
{
  hr = E_INVALIDARG;
  goto Exit;
}

// Get the current reserved value
hr = piQualifier->get_Reserved (&bReserved);
if(FAILED(hr))
  goto Exit;
 
// Update the reserved value if required
if (bReserved!= bNewReserved)
{
  hr = piQualifier->put_Reserved (bNewReserved);
  if(FAILED(hr))
    goto Exit;
}
Exit:
return hr;
}

Requirements

Header

SoftUSBif.h

通过