DescriptorType Property

项目
09/21/2010

The DescriptorType property gets or sets the value of the bDescriptorType field of the device descriptor, as defined in section 9.6.1 of the USB 2.0 specification.

This property is read/write.

Syntax

HRESULT put_DescriptorType(
  [in]           BYTE bDescriptorType
);

HRESULT get_DescriptorType(
  [out, retval]  BYTE *pbDescriptorType
);

Property Value

The new descriptor type.

Error Codes

DescriptorType returns S_OK if the operation succeeds or E_POINTER if the pbDescriptorType parameter is not a valid pointer.

Remarks

The following C++ code example shows how to get the DescriptorType property.

HRESULT CLoopBackDevice::GetDeviceType(BYTE *pbDescriptorType)
{
HRESULT hr = S_OK;
BYTE         bDescriptorType = 0;

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

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

//Initialize the return size
*pbDescriptorType = 0;

// Get the descriptor type
 hr = m_piDevice ->get_DescriptorType(pbDescriptorType);
Exit:
 return hr;
}

Requirements

Header

SoftUSBIf.h

通过