Serial port data show in textbox using C#

        private string rxString;
        private void mySerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            rxString = mySerialPort.ReadExisting();
            this.Invoke(new EventHandler(displayText));

        }

        private void displayText(object o, EventArgs e)
        {
            tbRX.AppendText(rxString);

        }