private void btnSendTrade_Click(object sender, EventArgs e)
        {
            NET_ITS_TRANS_INFO trade = new NET_ITS_TRANS_INFO();

            trade.sStartTime = new byte[20];
            trade.sEndTime   = new byte[20];
            //int a = Marshal.SizeOf(trade);
            trade.nPumpID     = (byte)comboNozzle.SelectedIndex;
            trade.nOilType    = 92;
            trade.fTradeLitre = 3.2f;
            trade.fTradeMoney = 35.0f;
            trade.fTradePrice = 6.80f;
            trade.fStartRead  = 1000.1f;
            trade.fEndRead    = 1003.3f;
            string time = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

            byte[] byTime = System.Text.Encoding.Default.GetBytes(time);
            Buffer.BlockCopy(byTime, 0, trade.sStartTime, 0, byTime.Length);
            Buffer.BlockCopy(byTime, 0, trade.sEndTime, 0, byTime.Length);
            HCNetSDK.NET_DVR_SendTrans(trade);
        }