Length Property

项目
09/21/2010

The Length property gets or sets the bLength field of the endpoint descriptor, as described in section 9.6.6 of the USB 2.0 specification.

This property is read/write.

Syntax

HRESULT put_Length(
  [in]           BYTE bLength
);

HRESULT get_Length(
  [out, retval]  BYTE *pbLength
);

Property Value

The new length of the endpoint descriptor.

Error Codes

Length returns S_OK if the operation succeeds or E_POINTER if the pbLength parameter is not a valid pointer.

Remarks

The following C++ code example shows how to get the length of the SoftUSBEndpoint descriptor.

HRESULT CLoopBackDevice::GetEndpointSize(BYTE *pbSize)
{
HRESULT hr = S_OK;
 if(NULL == pbSize)
{
 hr = E_POINTER;
 goto Exit;
}

// Initialize the return size
*pbSize = 0;


// Get the descriptor length
 hr = m_piEndpoint ->get_Length(pbSize);
 if(FAILED(hr))
 goto Exit;

Exit:
 return hr;
}

Requirements

Header

SoftUSBif.h

通过