NumInterfaces Property

项目
09/21/2010

The NumInterfaces property gets the bNumInterfaces field of the configuration descriptor, as described in section 9.6.3 of the USB 2.0 specification.

This property is read-only.

Syntax

HRESULT get_NumInterfaces(
  [out, retval]  BYTE *pbNumInterfaces
);

Property Value

A pointer to caller-allocated space to hold the number of interfaces that are associated with this configuration.

Error Codes

NumInterfaces returns S_OK if the operation succeeds or E_POINTER if the pbNumInterfaces parameter is not a valid pointer.

Remarks

The NumInterfaces property returns the number of unique interfaces that are associated with the configuration. Note that this number is not the same number that is returned from SoftUSBConfiguration.Interfaces.Count which includes all of the alternates for all of the interfaces as well.

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

 HRESULT GetNumInterfaces(ISoftUSBConfiguration *piConfig, BYTE *pbNumInterfaces)
{
 return piConfig->get_NumInterfaces(pbNumInterfaces);
}

Requirements

Header

SoftUSBif.h

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