源代码：

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Threading;

namespace 串口通信

{

public partial class frmMain : Form

{

public frmMain()

{

InitializeComponent();

}

public int iPort = 1; //1,2,3,4

public int iRate = 9600; //1200,2400,4800,9600

public byte bSize = 8; //8 bits

public byte bParity = 0; // 0-4=no,odd,even,mark,space

public byte bStopBits = 1; // 0,1,2 = 1, 1.5, 2

public int iTimeout = 1000;

public myCom com = new myCom();

public byte[] recb;

public int nub = 0;

//打开串口

public bool openCom()

{

try {

if (com.Opened)

{

com.Close();

com.Open();

}

else

{

com.Open();

}

return true;

}catch(Exception ex)

{

MessageBox.Show(ex.Message);

return false;

}

}

//显示包信息

public string disPackage(byte[] reb)

{

string temp = "";

foreach (byte b in reb)

temp += b.ToString("X2") + " ";

return temp;

}

//去掉字符数组中的空格

public string delSpace(string input)

{

string output = "";

for(int i=0;i

{

if(input!=' ')

output += input;

}

return output;

}

//发送数据包

public void sendPackage(byte[] bb)

{

int sendNum = 0;

try

{

sendNum = com.Write(bb);

Thread.Sleep(50);

this.txtShow.AppendText("\r\n发送数据："+disPackage(bb));

recb = com.Read(50);

this.txtShow.AppendText("\r\n接收到数据：" + disPackage(recb));

}catch(Exception ex)

{

MessageBox.Show(ex.Message);

}

}

//提取发送的数据包

public byte[] sendDB()

{

string temp = delSpace(this.txtSend.Text.Trim());

byte[] strTemp = new byte[50];

int j = 0;

try

{

for (int i = 0; i < temp.Length; i = i + 2, j++)

strTemp[j] = Convert.ToByte(temp.Substring(i, 2), 16);

}catch(Exception ex)

{

MessageBox.Show(ex.Message);

}

byte[] send = new byte[j];

Array.Copy(strTemp, send, j);

return send;

}

//点击发送按钮发送数据

private void button4_Click(object sender, EventArgs e)

{

if (this.txtSend.Text == "")

{

MessageBox.Show("发送数据为空！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);

return;

}

if (com.Opened)

{

byte[] temp = sendDB();

sendPackage(temp);

}

else

{

MessageBox.Show("串口已经关闭！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);

return;

}

}

//程序开启，串口初始化

private void Form1_Load(object sender, EventArgs e)

{

this.timer1.Enabled = true;

this.cboRate.SelectedIndex =5;

this.cboPortNo.SelectedIndex=0;

this.cboByteSize.SelectedIndex=3;

this.cboStopByte.SelectedIndex=1;

this.cboParity.SelectedIndex=0;

com.PortNum = iPort;

com.BaudRate = iRate;

com.ByteSize = bSize;

com.Parity = bParity;

com.StopBits = bStopBits;

com.ReadTimeout = iTimeout;

if(this.openCom())

{

this.txtShow.AppendText("串口初始化成功!...");

}else{

this.txtShow.AppendText("串口初始化失败!");

}

}

//保存配置

private void button1_Click(object sender, EventArgs e)

{

switch (this.cboPortNo.SelectedIndex)

{

case 0:

iPort = 1;

break;

case 1:

iPort = 2;

break;

case 2:

iPort = 3;

break;

case 3:

iPort = 4;

break;

}

//MessageBox.Show(iPort.ToString());

switch (this.cboParity.SelectedIndex)

{

case 0:

bParity = 0;

break;

case 1:

bParity = 1;

break;

case 2:

bParity = 2;

break;

case 3:

bParity = 3;

break;

case 4:

bParity = 4;

break;

}

//MessageBox.Show(bParity.ToString());

switch (this.cboStopByte.SelectedIndex)

{

case 0:

bStopBits =0;

break;

case 1:

bStopBits = 1;

break;

case 2:

bStopBits = 2;

break;

}

//MessageBox.Show(bParity.ToString());

com.PortNum = Convert.ToInt16(iPort);

com.BaudRate = Convert.ToInt16(this.cboRate.Text);

com.ByteSize = Convert.ToByte(this.cboByteSize.Text,10);

com.Parity = Convert.ToByte(bParity);

com.StopBits = Convert.ToByte(bStopBits);

if(this.openCom())

{

this.txtShow.AppendText("\r\n串口参数设置成功！...");

}else

{

this.txtShow.AppendText("\r\n串口参数设置失败！");

}

}

private void button3_Click(object sender, EventArgs e)

{

this.Dispose();

}

private void button5_Click(object sender, EventArgs e)

{

this.txtSend.Text = string.Empty;

// this.textBox2.Text = "";

}

//打开关闭按钮

private void button2_Click(object sender, EventArgs e)

{

if (this.btnCloseCom.Text == "关闭串口")

{

this.btnCloseCom.Text = "打开串口";

this.txtShow.AppendText("\r\n串口被关闭!");

this.cboPortNo.Enabled = true;

com.Close();

}

else

{

this.btnCloseCom.Text = "关闭串口";

this.txtShow.AppendText("\r\n串口成功开启!...");

this.cboPortNo.Enabled = false;

com.Open();

}

}

//打开关于窗口

private void button2_Click_1(object sender, EventArgs e)

{

frmAbout frm = new frmAbout();

frm.Show();

}

private void btnClearShow_Click(object sender, EventArgs e)

{

this.txtShow.Text = "";

}

private void timer1_Tick(object sender, EventArgs e)

{

this.TsslDate.Text = DateTime.Now.ToString();

this.TsslWeek.Text = DateTime.Now.ToString("dddd");

}

private void button1_Click_1(object sender, EventArgs e)

{

Help.ShowHelp(this, Application.StartupPath + "\\Readme.chm");

}

}

}

本程序需要用到一个C＋＋写的dll，功能是帮助初始化串口。(该dll文件已经放在bin\debug目录下)

以下是串口通信类：

using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;

using System.Configuration;

namespace 串口通信

{

public  class myCom

{

public myCom()

{

}

public int PortNum; //1,2,3,4

public int BaudRate; //1200,2400,4800,9600

public byte ByteSize; //8 bits

public byte Parity; // 0-4=no,odd,even,mark,space

public byte StopBits; // 0,1,2 = 1, 1.5, 2

public int ReadTimeout; //10

//comm port win32 file handle

private int hComm = -1;

public bool Opened = false;

//win32 api constants

private const uint GENERIC_READ = 0x80000000;

private const uint GENERIC_WRITE = 0x40000000;

private const int OPEN_EXISTING = 3;

private const int INVALID_HANDLE_VALUE = -1;

[StructLayout(LayoutKind.Sequential)]

private struct DCB

{

//taken from c struct in platform sdk

public int DCBlength;           // sizeof(DCB)

public int BaudRate;            // current baud rate

public int fBinary;          // binary mode, no EOF check

public int fParity;          // enable parity checking

public int fOutxCtsFlow;      // CTS output flow control

public int fOutxDsrFlow;      // DSR output flow control

public int fDtrControl;       // DTR flow control type

public int fDsrSensitivity;   // DSR sensitivity

public int fTXContinueOnXoff; // XOFF continues Tx

public int fOutX;          // XON/XOFF out flow control

public int fInX;           // XON/XOFF in flow control

public int fErrorChar;     // enable error replacement

public int fNull;          // enable null stripping

public int fRtsControl;     // RTS flow control

public int fAbortOnError;   // abort on error

public int fDummy2;        // reserved

public ushort wReserved;          // not currently used

public ushort XonLim;             // transmit XON threshold

public ushort XoffLim;            // transmit XOFF threshold

public byte ByteSize;           // number of bits/byte, 4-8

public byte Parity;             // 0-4=no,odd,even,mark,space

public byte StopBits;           // 0,1,2 = 1, 1.5, 2

public char XonChar;            // Tx and Rx XON character

public char XoffChar;           // Tx and Rx XOFF character

public char ErrorChar;          // error replacement character

public char EofChar;            // end of input character

public char EvtChar;            // received event character

public ushort wReserved1;         // reserved; do not use

}

[StructLayout(LayoutKind.Sequential)]

private struct COMMTIMEOUTS

{

public int ReadIntervalTimeout;

public int ReadTotalTimeoutMultiplier;

public int ReadTotalTimeoutConstant;

public int WriteTotalTimeoutMultiplier;

public int WriteTotalTimeoutConstant;

}

[StructLayout(LayoutKind.Sequential)]

private struct OVERLAPPED

{

public int  Internal;

public int  InternalHigh;

public int  Offset;

public int  OffsetHigh;

public int hEvent;

}

[DllImport("kernel32.dll")]

private static extern int CreateFile(

string lpFileName,                         // file name

uint dwDesiredAccess,                      // access mode

int dwShareMode,                          // share mode

int lpSecurityAttributes, // SD

int dwCreationDisposition,                // how to create

int dwFlagsAndAttributes,                 // file attributes

int hTemplateFile                        // handle to template file

);

[DllImport("kernel32.dll")]

private static extern bool GetCommState(

int hFile,  // handle to communications device

ref DCB lpDCB    // device-control block

);

[DllImport("kernel32.dll")]

private static extern bool BuildCommDCB(

string lpDef,  // device-control string

ref DCB lpDCB     // device-control block

);

[DllImport("kernel32.dll")]

private static extern bool SetCommState(

int hFile,  // handle to communications device

ref DCB lpDCB    // device-control block

);

[DllImport("kernel32.dll")]

private static extern bool GetCommTimeouts(

int hFile,                  // handle to comm device

ref COMMTIMEOUTS lpCommTimeouts  // time-out values

);

[DllImport("kernel32.dll")]

private static extern bool SetCommTimeouts(

int hFile,                  // handle to comm device

ref COMMTIMEOUTS lpCommTimeouts  // time-out values

);

[DllImport("kernel32.dll")]

private static extern bool ReadFile(

int hFile,                // handle to file

byte[] lpBuffer,             // data buffer

int nNumberOfBytesToRead,  // number of bytes to read

ref int lpNumberOfBytesRead, // number of bytes read

ref OVERLAPPED lpOverlapped    // overlapped buffer

);

[DllImport("kernel32.dll")]

private static extern bool WriteFile(

int hFile,                    // handle to file

byte[] lpBuffer,                // data buffer

int nNumberOfBytesToWrite,     // number of bytes to write

ref int lpNumberOfBytesWritten,  // number of bytes written

ref OVERLAPPED lpOverlapped        // overlapped buffer

);

[DllImport("kernel32.dll")]

private static extern bool CloseHandle(

int hObject   // handle to object

);

[DllImport("Comm.dll")]

public static extern void Init_Comm();

public void Open()

{

Init_Comm();

DCB dcbCommPort = new DCB();

COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();

// OPEN THE COMM PORT.

hComm = CreateFile("COM" + PortNum ,GENERIC_READ | GENERIC_WRITE,0, 0,OPEN_EXISTING,0,0);

// IF THE PORT CANNOT BE OPENED, BAIL OUT.

if(hComm == INVALID_HANDLE_VALUE)

{

throw(new ApplicationException("Comm Port Can Not Be Opened"));

}

// SET THE COMM TIMEOUTS.

GetCommTimeouts(hComm,ref ctoCommPort);

ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;

ctoCommPort.ReadTotalTimeoutMultiplier = 0;

ctoCommPort.WriteTotalTimeoutMultiplier = 0;

ctoCommPort.WriteTotalTimeoutConstant = 0;

SetCommTimeouts(hComm,ref ctoCommPort);

// SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.

// THERE ARE OTHER WAYS OF DOING SETTING THESE BUT THIS IS THE EASIEST.

// IF YOU WANT TO LATER ADD CODE FOR OTHER BAUD RATES, REMEMBER

// THAT THE ARGUMENT FOR BuildCommDCB MUST BE A POINTER TO A STRING.

// ALSO NOTE THAT BuildCommDCB() DEFAULTS TO NO HANDSHAKING.

dcbCommPort.DCBlength = Marshal.SizeOf(dcbCommPort);

GetCommState(hComm, ref dcbCommPort);

dcbCommPort.BaudRate=BaudRate;

dcbCommPort.Parity=Parity;

dcbCommPort.ByteSize=ByteSize;

dcbCommPort.StopBits=StopBits;

SetCommState(hComm, ref dcbCommPort);

Opened = true;

}

public void Close()

{

if (hComm!=INVALID_HANDLE_VALUE)

{

CloseHandle(hComm);

Opened=false;

}

}

public byte[] Read(int NumBytes)

{

byte[] BufBytes;

byte[] OutBytes;

BufBytes = new byte[NumBytes];

if (hComm!=INVALID_HANDLE_VALUE)

{

OVERLAPPED ovlCommPort = new OVERLAPPED();

int BytesRead=0;

ReadFile(hComm,BufBytes,NumBytes,ref BytesRead,ref ovlCommPort);

OutBytes = new byte[BytesRead];

Array.Copy(BufBytes,OutBytes,BytesRead);

}

else

{

throw(new ApplicationException("Comm Port Not Open"));

}

return OutBytes;

}

public int Write(byte[] WriteBytes)

{

int BytesWritten = 0;

if (hComm!=INVALID_HANDLE_VALUE)

{

OVERLAPPED ovlCommPort = new OVERLAPPED();

WriteFile(hComm,WriteBytes,WriteBytes.Length,ref BytesWritten,ref ovlCommPort);

}

else

{

throw(new ApplicationException("Comm Port Not Open"));

}

return BytesWritten;

}

}

}