INativeListener.OnGetDescriptorFromDevice Method

Native (C++):

HRESULT OnGetDescriptorFromDevice ( _FILETIME * fTime,void * pData,unsigned long Size,unsigned char Index,unsigned char DescriptorType,unsigned short LanguageId) ;

Parameters

fTime The time of the event. pData Pointer to a USBPACKET. Use it to manually parse all fields. See MFCSample for more details. Size Total size of USBPACKET and all payload data. Equals to nSize variable:

C++

          USBPACKET packet;
          ULONG nSize = packet->Size;

          USBPACKET_URB* pUrb = (USBPACKET_URB*)packet;
          ATLASSERT(pUrb->Size==nSize);

Index Specifies the device-defined index of the descriptor that is being retrieved or set. DescriptorType Indicates what type of descriptor is being retrieved or set. One of the following values must be specified: USB_DEVICE_DESCRIPTOR_TYPE/USB_CONFIGURATION_DESCRIPTOR_TYPE/USB_STRING_DESCRIPTOR_TYPE. LanguageId Specifies the language ID of the descriptor to be retrieved when USB_STRING_DESCRIPTOR_TYPE is set in DescriptorType. This member must be set to zero for any other value in DescriptorType.

Return Value

S_OK or standard OLE error code.

Remarks

Fired when URB packet with urb.UrbHeader.Function=URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE is received. See _URB_CONTROL_DESCRIPTOR_REQUEST for more details. The library decodes several parameters from this packet (see above).

< PreviousTopNext >