以下示例程序实现简单的Socket通信，可以开多个客户端。本机测试通过，未做联机测试。
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Server：
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using System.Net;
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using System.Net.Sockets;
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using System.Threading;
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using System.Collections;
\nnamespace MySocketServer1
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{
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public partial class Form1 : Form
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{
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private IPAddress serverIP = IPAddress.Parse(“127.0.0.1″);//以本机作测试
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private IPEndPoint serverFullAddr;//完整终端地址
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private Socket sock;
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private System.Timers.Timer myTimer;
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private ArrayList alSock;//当建立了多个连接时用于保存连接
\npublic Form1()
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{
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InitializeComponent();
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}
\nprivate void btStart_Click(object sender, EventArgs e)
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{
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serverFullAddr = new IPEndPoint(serverIP, 1000);//取端口号1000
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//构造Socket对象，套接字类型为“流套接字”，指定五元组中的协议元
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sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream,
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ProtocolType.Tcp);
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//指定五元组中的本地二元，即本地主机地址和端口号
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sock.Bind(serverFullAddr);
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//监听是否有连接传入，指定挂起的连接队列的最大值为20
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sock.Listen(20);
\nalSock = new ArrayList();
\n//构造定时器，时间间隙为1秒，即每隔一秒执行一次accept()方法，以获取连接请求队列中//第一个挂起的连接请求
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myTimer =new System.Timers.Timer(1000);
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myTimer.Elapsed +=new System.Timers.ElapsedEventHandler(myTimer_Elapsed);
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myTimer.Enabled = true;
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}
\nprivate void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
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{
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myTimer.Enabled = false;
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//执行accept()，当挂起队列为空时将阻塞本线程，同时由于上一语句，定时器将停止，直//至有连接传入
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Socket acceptSock = sock.Accept();
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//将accept()产生的Socket对象存入ArrayList
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alSock.Add(acceptSock);
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// 构造Threading.Timer对象，这将导致程序另启线程。线程将执行回调函数，该委托限制//函数参数须为object型。Threading.Timer构造器的第二个参数即传入回调函数的参数；第//三个参数指定调用回调函数之前的延时，取0则立即启动；最后一个参数指定调用回调函数//的时间间隔，取0则只执行一次。
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System.Threading.Timer ti = new System.Threading.Timer(new
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TimerCallback(ReceiveMsg), acceptSock, 0, 0);
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myTimer.Enabled = true;
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}
\nprivate void ReceiveMsg(object obj)
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{
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Socket acceptSock = (Socket)obj;
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try
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{
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while (true)
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{
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byte[] byteArray = new byte[100];
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acceptSock.Receive(byteArray);//接收数据
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//将字节数组转成字符串
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string strRec = System.Text.Encoding.UTF8.GetString(byteArray);
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if (this.rtbReceive.InvokeRequired)
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{
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this.rtbReceive.Invoke(new EventHandler(this.ChangeRickTextBox), new
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object[] { strRec, EventArgs.Empty });
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}
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}
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}
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catch(Exception ex)
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{
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acceptSock.Close();
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MessageBox.Show(“S:Receive Message Error”+ex.Message);
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}
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}
\nprivate void ChangeRickTextBox(object obj,EventArgs e)
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{
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string s = System.Convert.ToString(obj);
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this.rtbReceive.AppendText(s + Environment.NewLine);
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}
\nprivate void btSend_Click(object sender, EventArgs e)
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{
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Socket sc=null;
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byte[] byteSend =
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System.Text.Encoding.UTF8.GetBytes(this.tbSend.Text.ToCharArray());
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try
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{
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//同时存在若干个客户端连接时，在textBox1中输入要发送的是哪个连接
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int index = int.Parse(this.textBox1.Text.Trim());
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sc = (Socket)alSock[index - 1];
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//发送数据
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sc.Send(byteSend);
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}
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catch(Exception ex)
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{
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if(sc != null)
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{
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sc.Close();
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}
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MessageBox.Show(“S:Send Message Error”+ex.Message);
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}
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}
\nprivate void btClose_Click(object sender, EventArgs e)
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{
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try
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{
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Application.Exit();
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}
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catch (Exception ex)
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{
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MessageBox.Show(“S:Close Socket Error” + ex.Message);
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}
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}
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}
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}
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== == == == == == == == == == == == == == == == == == == == == == == == == == == == == == == ==
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Client:
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using System.Net;
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using System.Net.Sockets;
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using System.Threading;
\nnamespace MySocketClient1
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{
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public partial class Form1 : Form
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{
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private IPAddress serverIP = IPAddress.Parse(“127.0.0.1″);
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private IPEndPoint serverFullAddr;
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private Socket sock;
\npublic Form1()
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{
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InitializeComponent();
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}
\nprivate void btConnect_Click(object sender, EventArgs e)
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{
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try
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{
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serverFullAddr = new IPEndPoint(serverIP, 1000);
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sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream,
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ProtocolType.Tcp);
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sock.Connect(serverFullAddr);//建立与远程主机的连接
\n//启动新线程用于接收数据
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Thread t = new Thread(new ThreadStart(ReceiveMsg));
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t.Name = “Receive Message”;
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//一个线程或者是后台线程或者是前台线程。后台线程与前台线程类似，区别是后台线//程不会防止进程终止。一旦属于某一进程的所有前台线程都终止，公共语言运行库就//会通过对任何仍然处于活动状态的后台线程调用 Abort 来结束该进程。
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t.IsBackground = true;
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t.Start();
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}
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catch(Exception ex)
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{
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MessageBox.Show(ex.Message);
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}
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}
\nprivate void ReceiveMsg()
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{
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try
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{
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while (true)
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{
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byte[] byteRec = new byte[100];
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this.sock.Receive(byteRec);
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string strRec = System.Text.Encoding.UTF8.GetString(byteRec);
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if (this.rtbReceive.InvokeRequired)
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{
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this.rtbReceive.Invoke(new EventHandler(ChangeRtb), new object[]
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{ strRec, EventArgs.Empty });
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}
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}
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}
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catch(Exception ex)
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{
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MessageBox.Show(“Receive Message Error”+ex.Message);
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}
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}
\nprivate void ChangeRtb(object obj, EventArgs e)
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{
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string s = System.Convert.ToString(obj);
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this.rtbReceive.AppendText(s + Environment.NewLine);
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}
\nprivate void btSend_Click(object sender, EventArgs e)
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{
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byte[] byteSend =
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System.Text.Encoding.UTF8.GetBytes(this.tbSend.Text.ToCharArray());
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try
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{
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this.sock.Send(byteSend);
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}
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catch
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{
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MessageBox.Show(“Send Message Error”);
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}
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}
\nprivate void btClose_Click(object sender, EventArgs e)
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{
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try
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{
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this.sock.Shutdown(SocketShutdown.Receive);
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this.sock.Close();
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Application.Exit();
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}
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catch
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{
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MessageBox.Show(“Exit Error”);
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}
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}
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}
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}
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不解之处：
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Client端红色标注语句：this.sock.Shutdown(SocketShutdown.Receive)，如改成
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this.sock.Shutdown(SocketShutdown.Both);或this.sock.Shutdown(SocketShutdown.Send);
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则当点击Cloce按钮时，CPU使用率疯涨到100%，而使用this.sock.Shutdown(SocketShutdown.Receive);
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或不调用Shutdown()方法则没有这个问题。难道客户端不应该用Shutdown()？
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来源:网络
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