基于TCP协议的发送和接收端

TCP协议的接收端

using System.Net.Sockets; //使用到TcpListen类
using System.Threading; //使用到线程
using System.IO; //使用到StreamReader类

int port = 8000; //定义侦听端口号
private Thread thThreadRead; //创建线程，用以侦听端口号，接收信息
private TcpListener tlTcpListen; //侦听端口号
private bool blistener = true; //设定标示位，判断侦听状态
private NetworkStream nsStream; //创建接收的基本数据流  
private StreamReader srRead;
private System.Windows.Forms.StatusBar statusBar1;
private System.Windows.Forms.Button button1;
private System.Windows.Forms.ListBox listBox1; //从网络基础数据流中读取数据
private TcpClient tcClient;

private void Listen()
{
    try
    {
        tlTcpListen = new TcpListener(port); //以8000端口号来初始化TcpListener实例
        tlTcpListen.Start(); //开始监听
        statusBar1.Text = "正在监听...";
        tcClient = tlTcpListen.AcceptTcpClient(); //通过TCP连接请求
        nsStream = tcClient.GetStream(); //获取用以发送、接收数据的网络基础数据流
        srRead = new StreamReader(nsStream);//以得到的网络基础数据流来初始化StreamReader实例
        statusBar1.Text = "已经连接！";

        while (blistener) //循环侦听
        {
            string sMessage = srRead.ReadLine();//从网络基础数据流中读取一行数据 
            if (sMessage == "STOP") //判断是否为断开TCP连接控制码
            {
                tlTcpListen.Stop(); //关闭侦听
                nsStream.Close(); //释放资源
                srRead.Close();
                statusBar1.Text = "连接已经关闭！";
                thThreadRead.Abort(); //中止线程
                return;
            }

            string sTime = DateTime.Now.ToShortTimeString(); //获取接收数据时的时间
            listBox1.Items.Add(sTime + " " + sMessage);
        }
    }
    catch (System.Security.SecurityException)
    {
        MessageBox.Show("侦听失败！", "错误");
    }
}

//开始监听
private void button1_Click(object sender, System.EventArgs e)
{
    thThreadRead = new Thread(new ThreadStart(Listen));
    thThreadRead.Start();//启动线程           
    button1.Enabled = false;
}

// 清理所有正在使用的资源。
protected override void Dispose(bool disposing)
{
    try
    {
        tlTcpListen.Stop(); //关闭侦听 
        nsStream.Close();
        srRead.Close();//释放资源 
        thThreadRead.Abort();//中止线程 
    }
    catch { }

    if (disposing)
    {
        if (components != null)
        {
            components.Dispose();
        }
    }
    base.Dispose(disposing);
}

TCP协议的发送端

using System.Net.Sockets; //使用到TcpListen类
using System.Threading; //使用到线程
using System.IO; //使用到StreamWriter类
using System.Net; //使用IPAddress类、IPHostEntry类等

private StreamWriter swWriter; //用以向网络基础数据流传送数据
private NetworkStream nsStream; //创建发送数据的网络基础数据流
private TcpClient tcpClient;
private System.Windows.Forms.Button button1;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button button2;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.StatusBar statusBar1;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2; //通过它实现向远程主机提出TCP连接申请　
private bool tcpConnect = false; //定义标识符，用以表示TCP连接是否建立

//连接
private void button1_Click(object sender, System.EventArgs e)
{
    IPAddress ipRemote;
    try
    {
        ipRemote = IPAddress.Parse(textBox1.Text);
    }
    catch //判断给定的IP地址的合法性
    {
        MessageBox.Show("输入的IP地址不合法！", "错误提示！");
        return;
    }

    IPHostEntry ipHost;
    try
    {
        ipHost = Dns.Resolve(textBox1.Text);
    }
    catch //判断IP地址对应主机是否在线
    {
        MessageBox.Show("远程主机不在线！", "错误提示！");
        return;
    }

    string sHostName = ipHost.HostName;
    try
    {
        TcpClient tcpClient = new TcpClient(sHostName, 8000);//对远程主机的8000端口提出TCP连接申请
        nsStream = tcpClient.GetStream();//通过申请，并获取传送数据的网络基础数据流
        swWriter = new StreamWriter(nsStream);//使用获取的网络基础数据流来初始化StreamWriter实例
        button1.Enabled = false;
        button2.Enabled = true;
        tcpConnect = true;
        statusBar1.Text = "已经连接！";
    }
    catch
    {
        MessageBox.Show("无法和远程主机8000端口建立连接！", "错误提示！");
        return;
    }
}

//发送
private void button2_Click(object sender, System.EventArgs e)
{
    if (textBox2.Text != "")
    {
        swWriter.WriteLine(textBox2.Text);//刷新当前数据流中的数据
        swWriter.Flush();
    }
    else
    {
        MessageBox.Show("发送信息不能为空！", "错误提示！");
    }
}

// 清理所有正在使用的资源。
protected override void Dispose(bool disposing)
{
    if (tcpConnect)
    {
        swWriter.WriteLine("STOP"); //发送控制码
        swWriter.Flush(); //刷新当前数据流中的数据
        nsStream.Close(); //清除资源
        swWriter.Close();
    }

    if (disposing)
    {
        if (components != null)
        {
            components.Dispose();
        }
    }
    base.Dispose(disposing);
}