程序代码：

            this.Invoke((EventHandler)(delegate
            {
                builder.Append( Encoding.ASCII.GetString(buf));
                //this.rTxcommon.AppendText(builder.ToString());
                getStr += builder.ToString();
                switch (getStr)
                {
                    case "00\r\n":
                        if (boolDial == true)
                        {
                            this.lblsig3.Visible = true;
                        }
                        if (boolSetno == true)
                        {
                            this.rTxcommon.AppendText("Set No. OK\r\n");
                        }
                        break;
                    case "FF\r\n":
                        this.lblsig3.Visible = false;
                        break;
                    default:
                        this.rTxcommon.AppendText(":" + getStr);
                        break;
                }
            }));