[源代码]C#中串口通信编程 [zt]
最近在论坛看到很多人对这个由兴趣，遇到一篇好文章，转给大家。[简介]
本文将介绍如何在.NET平台下使用C#创建串口通信程序，.NET 2.0提供了串口通信的功能，其命名
空间是System.IO.Ports。这个新的框架不但可以访问计算机上的串口，还可以和串口设备进行通信。
我们将使用标准的RS 232 C 在PC间通信。它工作在全双工模式下，而且我们不打算使用任何的握手
或流控制器，而是使用无modem连接。
命名空间
System.IO.Ports命名空间中最重用的是SerialPort 类。
创建SerialPort 对象
通过创建SerialPort 对象，我们可以在程序中控制串口通信的全过程。
我们将要用到的SerialPort 类的方法：
ReadLine()：从输入缓冲区读一新行的值，如果没有，会返回NULL
WriteLine(string)：写入输出缓冲
Open()：打开一个新的串口连接
Close()：关闭
Code:
//create a Serial Port object
SerialPort sp = new SerialPort ();
SerialPort sp = new SerialPort ();
默认情况下，DataBits 值是8，StopBits 是1，通信端口是COM1。这些都可以在下面的属性中重新设置
：
BaudRate：串口的波特率
StopBits：每个字节的停止位数量
ReadTimeout：当读操作没有完成时的停止时间。单位，毫秒
还有不少其它公共属性，自己查阅MSDN。
串口的硬件知识
在数据传输的时候，每个字节的数据通过单个的电缆线传输。包包括开始位，数据，结束为。一旦
开始位传出，后面就会传数据，可能是5，6，7或8位，就看你的设定了。发送和接收必须设定同样
的波特率和数据位数。
无猫模式
没有Modem模式的电缆只是简单地交叉传送和接收线。同样DTR & DSR, 和 RTS & CTS也需要交叉。
RS232针图
这里，我们三条线。互连2和3（一段的2pin连接3pin），连接两端的5pin。
[示例程序]
主程序
如果想使用默认属性，按“Save Status”按钮，如果想改变属性按“Property”。它会弹出下图：
设定好之后，可以通信了。
主窗口的代码
Code:
#region Using directives
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using System.IO.Ports;
#endregion
namespace Serialexpample
{
partial class Form1 : Form
{
//create instance of property page
//property page is used to set values for stop bits and
//baud rate
PropertyPage pp = new PropertyPage();
//create an Serial Port object
SerialPort sp = new SerialPort();
public Form1()
{
InitializeComponent();
}
private void propertyButton_Click(object sender, EventArgs e)
{
//show property dialog
pp.ShowDialog();
propertyButton.Hide();
}
private void sendButton_Click(object sender, EventArgs e)
{
try
{
//write line to serial port
sp.WriteLine(textBox.Text);
//clear the text box
textBox.Text = "";
}
catch (System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
private void ReadButton_Click(object sender, EventArgs e)
{
try
{
//clear the text box
textBox.Text = "";
//read serial port and displayed the data in text box
textBox.Text = sp.ReadLine();
}
catch(System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
MessageBox.Show("Do u want to Close the App");
sp.Close();
}
private void startCommButton_Click(object sender, EventArgs e)
{
startCommButton.Hide();
sendButton.Show();
readButton.Show();
textBox.Show();
}
//when we want to save the status(value)
private void saveStatusButton_Click_1(object sender, EventArgs e)
{
//display values
//if no property is set the default values
if (pp.bRate == "" && pp.sBits == "")
{
dataBitLabel.Text = "BaudRate = " + sp.BaudRate.ToString();
readTimeOutLabel.Text = "StopBits = " + sp.StopBits.ToString();
}
else
{
dataBitLabel.Text = "BaudRate = " + pp.bRate;
readTimeOutLabel.Text = "StopBits = " + pp.sBits;
}
parityLabel.Text = "DataBits = " + sp.DataBits.ToString();
stopBitLabel.Text = "Parity = " + sp.Parity.ToString();
readTimeOutLabel.Text = "ReadTimeout = " +
sp.ReadTimeout.ToString();
if (propertyButton.Visible == true)
propertyButton.Hide();
saveStatusButton.Hide();
startCommButton.Show();
try
{
//open serial port
sp.Open();
//set read time out to 500 ms
sp.ReadTimeout = 500;
}
catch (System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
}
}
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using System.IO.Ports;
#endregion
namespace Serialexpample
{
partial class Form1 : Form
{
//create instance of property page
//property page is used to set values for stop bits and
//baud rate
PropertyPage pp = new PropertyPage();
//create an Serial Port object
SerialPort sp = new SerialPort();
public Form1()
{
InitializeComponent();
}
private void propertyButton_Click(object sender, EventArgs e)
{
//show property dialog
pp.ShowDialog();
propertyButton.Hide();
}
private void sendButton_Click(object sender, EventArgs e)
{
try
{
//write line to serial port
sp.WriteLine(textBox.Text);
//clear the text box
textBox.Text = "";
}
catch (System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
private void ReadButton_Click(object sender, EventArgs e)
{
try
{
//clear the text box
textBox.Text = "";
//read serial port and displayed the data in text box
textBox.Text = sp.ReadLine();
}
catch(System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
MessageBox.Show("Do u want to Close the App");
sp.Close();
}
private void startCommButton_Click(object sender, EventArgs e)
{
startCommButton.Hide();
sendButton.Show();
readButton.Show();
textBox.Show();
}
//when we want to save the status(value)
private void saveStatusButton_Click_1(object sender, EventArgs e)
{
//display values
//if no property is set the default values
if (pp.bRate == "" && pp.sBits == "")
{
dataBitLabel.Text = "BaudRate = " + sp.BaudRate.ToString();
readTimeOutLabel.Text = "StopBits = " + sp.StopBits.ToString();
}
else
{
dataBitLabel.Text = "BaudRate = " + pp.bRate;
readTimeOutLabel.Text = "StopBits = " + pp.sBits;
}
parityLabel.Text = "DataBits = " + sp.DataBits.ToString();
stopBitLabel.Text = "Parity = " + sp.Parity.ToString();
readTimeOutLabel.Text = "ReadTimeout = " +
sp.ReadTimeout.ToString();
if (propertyButton.Visible == true)
propertyButton.Hide();
saveStatusButton.Hide();
startCommButton.Show();
try
{
//open serial port
sp.Open();
//set read time out to 500 ms
sp.ReadTimeout = 500;
}
catch (System.Exception ex)
{
baudRatelLabel.Text = ex.Message;
}
}
}
}
属性设置对话框代码：
Code:
#region Using directives
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
#endregion
namespace Serialexpample
{
partial class PropertyPage : Form
{
//variables for storing values of baud rate and stop bits
private string baudR="";
private string stopB="";
//property for setting and getting baud rate and stop bits
public string bRate
{
get
{
return baudR;
}
set
{
baudR = value;
}
}
public string sBits
{
get
{
return stopB;
}
set
{
stopB = value;
}
}
public PropertyPage()
{
InitializeComponent();
}
private void cancelButton_Click(object sender, EventArgs e)
{
this.bRate = "";
this.sBits = "";
//close form
this.Close();
}
private void okButton_Click_1(object sender, EventArgs e)
{
//here we set the value for stop bits and baud rate.
this.bRate = BaudRateComboBox.Text;
this.sBits = stopBitComboBox.Text;
//
this.Close();
}
}
}
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
#endregion
namespace Serialexpample
{
partial class PropertyPage : Form
{
//variables for storing values of baud rate and stop bits
private string baudR="";
private string stopB="";
//property for setting and getting baud rate and stop bits
public string bRate
{
get
{
return baudR;
}
set
{
baudR = value;
}
}
public string sBits
{
get
{
return stopB;
}
set
{
stopB = value;
}
}
public PropertyPage()
{
InitializeComponent();
}
private void cancelButton_Click(object sender, EventArgs e)
{
this.bRate = "";
this.sBits = "";
//close form
this.Close();
}
private void okButton_Click_1(object sender, EventArgs e)
{
//here we set the value for stop bits and baud rate.
this.bRate = BaudRateComboBox.Text;
this.sBits = stopBitComboBox.Text;
//
this.Close();
}
}
}
