基于c#de串口通讯问题

我想实时获取从串口里面传输出来的字符串数据，可是为什么老是显示不出来呢，求高手解答，本人渣渣，谢谢了

 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        string data;
        Boolean status = false;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            serialPort1.PortName = "COM3";
            serialPort1.BaudRate = 57600;
            serialPort1.Encoding = Encoding.BigEndianUnicode;
            serialPort1.Open();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            serialPort1.Close();
            Close();
        }
        private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            data = serialPort1.ReadExisting();
            this.Invoke(new EventHandler(DisplayText));
        }

        private void DisplayText(object sender, EventArgs e)
        {
            char[] data1 = data.ToCharArray();
            textBox1.Text = data1.ToString();

        }


    }
}

觉得这个是异步的问题，DataReceived的时候给data赋值，DisplayText里取的时候DataReceived会不会触发了，这个时候serialPort1.ReadExisting()为空，所以DisplayText显示不了，纯粹猜测，实际调一下看看吧， DataReceived加个断点看看有数据不