我想在Visual c＃2010中创建一个包含按钮，文本框，串口的表单。我的目标是当按下按钮时，来自串口的数据必须显示在文本框中。我从教程中复制了以下代码。文本框没有显示任何内容。这是代码
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 ser1
{
public partial class Form1 : Form
{
private string RxString;
public Form1()
{
InitializeComponent();
}
private void buttonStart_Click(object sender, EventArgs e)
{
serialPort1.PortName = "COM4";
serialPort1.BaudRate = 9600;
serialPort1.Open();
if (serialPort1.IsOpen)
{
buttonStart.Enabled = false;
buttonStop.Enabled = true;
textBox1.ReadOnly = false;
}
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
// If the port is closed, don't try to send a character.
if (!serialPort1.IsOpen) return;
// If the port is Open, declare a char[] array with one element.
char[] buff = new char[1];
// Load element 0 with the key character.
buff[0] = e.KeyChar;
// Send the one character buffer.
serialPort1.Write(buff, 0, 1);
// Set the KeyPress event as handled so the character won't
// display locally. If you want it to display, omit the next line.
e.Handled = true;
}
private void DisplayText(object sender, EventArgs e)
{
textBox1.Text=RxString.Trim();
}
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
RxString = serialPort1.ReadExisting();
this.Invoke(new EventHandler(DisplayText));
}
private void buttonStop_Click(object sender, EventArgs e)
{
if (serialPort1.IsOpen)
{
serialPort1.Close();
buttonStart.Enabled = true;
buttonStop.Enabled = false;
textBox1.ReadOnly = true;
}
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (serialPort1.IsOpen) serialPort1.Close();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
}“