c#怎样能在textBox中动态显示串口接收到的数据

 private void axMSComm1_OnComm(object sender, EventArgs e)
        {
            string strln = "";
            string strln2 = "μGy/h";
            string strln3 = "";
            byte[] bytln;
            object objln;            int i;            axMSComm1.InputMode = MSCommLib.InputModeConstants.comInputModeBinary;
            axMSComm1.InputLen = 8;
            objln = axMSComm1.Input;
bytln = (byte[])objln;            if (bytln != null)
            {
                for (i = 0; i <= (bytln.Length - 1); i++)
                { 
                  strln += bytln[i].ToString("X");
                   
                }
        switch (Convert.ToInt32(bytln[1])) //判断位置                    {
                        case 65:
                            if ((bytln[4] << 8 | bytln[5]) < 100)
                            {
                                strln3 = "0" + (bytln[4] << 8 | bytln[5]);
                            }
                            else
                                strln3 = (bytln[4] << 8 | bytln[5]) + "";
                            textBox1.Text = "";                            textBox1.Text = (bytln[2] << 8 | bytln[3]) + "." + strln3 + strln2;
                           break;
                        case 66:
                            if ((bytln[4] << 8 | bytln[5]) < 100)
                            {
                                strln3 = "0" + (bytln[4] << 8 | bytln[5]);
                            }
                            else
                                strln3 = (bytln[4] << 8 | bytln[5]) + " ";
                            textBox2.Text = "";
                            textBox2.Text = (bytln[2] << 8 | bytln[3]) + "." + strln3 + strln2;
                        //System.Threading.Thread.CurrentThread.Join(1000);
                            break;
                    default:
                            Console.WriteLine("无数据传送");                            break;
}
这个代码只能显示刚运行接收的那个数据，而单步调试时，就可以看到TextBox中的数据是变动的，望各位前辈指点