WMI方式检测：
    wmi = WIN32OLE.connect("winmgmts://")
    devices = wmi.ExecQuery("Select * From Win32_USBControllerDevice")
    devices.each do |device|
      device_name = device.Dependent.gsub('"', '').split('=')[1]
      usb_devices = wmi.ExecQuery("Select * From Win32_PnPEntity Where DeviceID = '#{device_name}'")
      for usb_device in usb_devices do
        puts usb_device.Description
        if usb_device.Description == 'USB Mass Storage Device'&&如是扫描枪的话应该是“XXXX SCANNER”之类
          # DO SOMETHING HERE
        end
      end
    end