public class dllTest
    {
        public AxActQJ71E71TCP PlcSocket = null;

        public dllTest(ref AxActQJ71E71TCP _PlcSocket)
        {
             PlcSocket = _PlcSocket;
        }

        public override bool HandControlValve7_Value()
        {
            this._szDevice = "D136";
            eData = new int[4] { 1, 2, 3, 4 };
            int iRet = PlcSocket.EntryDeviceStatus(this._szDevice,1, 1, ref _eData[0]);
            PlcSocket.OnDeviceStatus += new _IActQJ71E71TCPEvents_OnDeviceStatusEventHandler(PlcSocket_OnDeviceStatus);

            return false;    
        }

        public void PlcSocket_OnDeviceStatus(object sender, _IActQJ71E71TCPEvents_OnDeviceStatusEvent e)
        {
            if (e.szDevice == "D136")
            {
                PlcSocket.FreeDeviceStatus();
            }
        }
｝

       public AxActQJ71E71TCP GuiPlcSocket = new AxActQJ71E71TCP();

       private void button3_Click(object sender, EventArgs e)
        {
              dllTest dlltst = new dllTest(ref GuiPlcSocket );
              dlltst.HandControlValve7_Value();
        }