枚举USB设备，找到了需要的设备，怎么去打开设备！

1 Call SetupDiGetClassDevs(interface_guid, 0, 0, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE) to get a list of devices.

2 Call SetupDiEnumDeviceInterfaces() to get a list of available device interfaces.

3 Call SetupDiGetDeviceInterfaceDetail() 

	g____usb_count = 0;

	*devicename = 0;

	//查找本系统中HID类的GUID标识

	//在我的机器上应该找出来

	//{4D1E55B2-F16F-11CF-88CB-001111000030}

	HidD_GetHidGuid( &guidHID );



	//准备查找符合HID规范的USB设备

	hDevInfo = SetupDiGetClassDevs( &guidHID, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE );

	if( INVALID_HANDLE_VALUE == hDevInfo )

	{

		//INIT;

		//mul( 0 );

		//MASK( "SetupDiGetClassDevs失败\r\n" );

		//SHOW;

		return g____usb_count;

	}



	// 查找USB设备接口

	memset( &InterfaceData, 0, sizeof( SP_DEVICE_INTERFACE_DATA ) );

    InterfaceData.cbSize = sizeof( SP_DEVICE_INTERFACE_DATA );



	i = 0;



	do

	{

		//枚举设备接口

		if( !SetupDiEnumDeviceInterfaces( hDevInfo, NULL, &guidHID, i, &InterfaceData ) )

		{

			SetupDiDestroyDeviceInfoList( hDevInfo );

			//INIT;

			//mul( 0 );

			//MASK( "SetupDiGetClassDevs失败\r\n" );

			//SHOW;

			return g____usb_count;

		}



		//获取设备详细信息

		length = 0;

		if( !SetupDiGetDeviceInterfaceDetail( hDevInfo, &InterfaceData, NULL, 0, &length, NULL ) )

		{

			err = GetLastError();

			if( ERROR_INSUFFICIENT_BUFFER != err )

			{

				i++;

				continue;

			}

		}



		DetailData = ( PSP_DEVICE_INTERFACE_DETAIL_DATA )LocalAlloc( LMEM_ZEROINIT, length );

		if( NULL == DetailData )

		{

			SetupDiDestroyDeviceInfoList( hDevInfo );

			//INIT;

			//mul( 0 );

			//MASK( "LocalAlloc失败\r\n" );

			//SHOW;

			return g____usb_count;

		}



		DetailData->cbSize = sizeof( SP_DEVICE_INTERFACE_DETAIL_DATA );

		if( !SetupDiGetDeviceInterfaceDetail( hDevInfo, &InterfaceData, DetailData, length, NULL, NULL ) )

		{

			LocalFree( DetailData );

			i++;

			continue;

		}



		//打开设备,获取句柄

		g____usb_handle_write[ g____usb_count ] = CreateFile( DetailData->DevicePath, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, ( LPSECURITY_ATTRIBUTES )NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );