IWDFUsbInterface::GetNumEndPoints method

The GetNumEndPoints method retrieves the number of endpoints (pipes) on a USB interface.

Syntax


UCHAR GetNumEndPoints();

Parameters

This method has no parameters.

Return value

GetNumEndPoints returns the number of endpoints on the USB interface.

Remarks

The GetNumEndPoints method is provided for convenience because a UMDF driver can obtain the number of endpoints from the bNumEndpoints member of the USB_INTERFACE_DESCRIPTOR structure that the driver retrieves when it calls the IWDFUsbInterface::GetInterfaceDescriptor method.

Examples

The following code example retrieves the number of pipes on a USB interface and then retrieves particular types of pipes.


 HRESULT  hr;
 UCHAR  NumEndPoints;
 NumEndPoints = pIUsbInterface->GetNumEndPoints();

 if (NumEndPoints != NUM_OSRUSB_ENDPOINTS) {
     hr = E_UNEXPECTED;
 }
 if (SUCCEEDED(hr))  {
     for (UCHAR PipeIndex = 0; PipeIndex < NumEndPoints; PipeIndex++) {
     hr = pIUsbInterface->RetrieveUsbPipeObject(PipeIndex, 
                                                &pIUsbPipe);
     if (FAILED(hr)) {
        // Output an error.
     }
     else {
         if ( pIUsbPipe->IsInEndPoint() && (UsbdPipeTypeBulk == pIUsbPipe->GetType()) ) {
             pIUsbInputPipe = pIUsbPipe;
         }
         else if ( pIUsbPipe->IsOutEndPoint() && (UsbdPipeTypeBulk == pIUsbPipe->GetType()) )
         {
              pIUsbOutputPipe = pIUsbPipe;
         }
         else
              {
                  SAFE_RELEASE(pIUsbPipe);
              }
          }

Requirements

End of support	Unavailable in UMDF 2.0 and later.
Minimum UMDF version	1.5
Header	Wudfusb.h (include Wudfusb.h)
DLL	WUDFx.dll