begin
  try
    try
      aList:=TStringList.Create;
      Locator := CreateOleObject('WbemScripting.SWbemLocator');
      WMI := Locator.ConnectServer('.', '', '','');
      Ret := WMI.ExecQuery('SELECT * FROM Win32_USBHub');//这里Win32_USBHub为检测项，详见下表
      Enum:= IUnknown(RET._NewEnum) as IEnumVariant;
      //Tmp为检测到返回的数据集合，其中PNPDeviceID为集合中的对象，包含了PID和VID码
      while (Enum.Next(1, Tmp, Value) = S_OK) do   aList.Add(Tmp.PNPDeviceID);
      //if aList.IndexOf('USB\VID_1267&PID_5AA5\5&16BBD8B4&0&1')>0 then  //设备存在
      if pos('USB\VID_1267',alist.CommaText)>0 then
      begin
        //BindWindow(form1.Handle);//绑定窗口
        BindWindow(handle);//绑定窗口
        StatusBar1.Panels[0].Text:='已连接';
        button1.Tag :=100;
        button1.Caption :='解除绑定';
      end
      else
      begin
        button1.Tag :=0;
        button1.Caption :='窗口绑定';
        BindWindow(handle);//绑定窗口
        StatusBar1.Panels[0].Text:='已断开';

      end;
    finally
      alist.Destroy;
    end;
  except
    on e:exception do
    exit;
  end; 
end;