简单的C# Socket通信实例

一、套接字（socket）概念

套接字（socket）是通信的基石，是支持TCP/IP协议的网络通信的基本操作单元。它是网络通信过程中端点的抽象表示，包含进行网络通信必须的五种信息：连接使用的协议，本地主机的IP地址，本地进程的协议端口，远地主机的IP地址，远地进程的协议端口。
　　应用层通过传输层进行数据通信时，TCP会遇到同时为多个应用程序进程提供并发服务的问题。多个TCP连接或多个应用程序进程可能需要通过同一个 TCP协议端口传输数据。为了区别不同的应用程序进程和连接，许多计算机操作系统为应用程序与TCP／IP协议交互提供了套接字(Socket)接口。应 用层可以和传输层通过Socket接口，区分来自不同应用程序进程或网络连接的通信，实现数据传输的并发服务。

二、建立socket连接

建立Socket连接至少需要一对套接字，其中一个运行于客户端，称为ClientSocket ，另一个运行于服务器端，称为ServerSocket 。
　　套接字之间的连接过程分为三个步骤：服务器监听，客户端请求，连接确认。

1. 服务器监听：服务器端套接字并不定位具体的客户端套接字，而是处于等待连接的状态，实时监控网络状态，等待客户端的连接请求
2. 客户端请求：指客户端的套接字提出连接请求，要连接的目标是服务器端的套接字。为此，客户端的套接字必须首先描述它要连接的服务器的套接字，指出服务器端套接字的地址和端口号，然后就向服务器端套接字提出连接请求。
3. 连接确认：当服务器端套接字监听到或者说接收到客户端套接字的连接请求时，就响应客户端套接字的请求，建立一个新的线程，把服务器端套接字的描述发给客户 端，一旦客户端确认了此描述，双方就正式建立连接。而服务器端套接字继续处于监听状态，继续接收其他客户端套接字的连接请求。

三、服务端与客户端代码

服务端前台XMAL

 <Window x:Class="Socket通信.MainWindow"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
          xmlns:local="clr-namespace:Socket通信"
          mc:Ignorable="d"
          Title="服务端" Height="" Width="" Loaded="Window_Loaded" >
      <Grid>
          <Grid.RowDefinitions>
              <RowDefinition Height="50*"/>
              <RowDefinition Height="190*"/>
              <RowDefinition Height="81*"/>
          </Grid.RowDefinitions>
          <Grid Grid.Row="">
              <WrapPanel VerticalAlignment="Center">
                  <Label Padding="">IP:</Label>
                  <TextBox Padding="" Width="" Name="IP"></TextBox>
                  <Label Padding="">Port:</Label>
                  <TextBox Padding="" Width="" Name="Port"></TextBox>
                  <Button Padding="" Margin="" Click="Start_View_Click">开始监听</Button>
                  <Button Padding="" Margin="" Click="Stop_Click">停止监听</Button>
              </WrapPanel>
          </Grid>
          <Grid Grid.Row="">
              <ListBox Name="ListConnet"></ListBox>
          </Grid>
          <Grid Grid.Row="">
              <Grid.ColumnDefinitions>
                  <ColumnDefinition Width="405*"/>
                  <ColumnDefinition Width="113*"/>
              </Grid.ColumnDefinitions>

                  <TextBox Name="SentConnet"></TextBox>
                  <Button Grid.Column="" Click="Send_Click">发送</Button>

          </Grid>
      </Grid>
  </Window>

服务端后台代码

 using System;
  using System.Net;
  using System.Net.Sockets;
  using System.Text;
  using System.Threading;
  using System.Windows;

 namespace Socket通信
 {
      /// <summary>
      /// MainWindow.xaml 的交互逻辑
     /// </summary>
      public partial class MainWindow : Window
      {
          public MainWindow()
          {
              InitializeComponent();
          }
          Socket socketSend;
          private void Start_View_Click(object sender, RoutedEventArgs e)
          {
              try
               {
                  //点击开始监听时 在服务端创建一个负责监听IP和端口号的Socket
                   Socket socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                   IPAddress ip = IPAddress.Any;                //创建对象端口
                  IPEndPoint point = new IPEndPoint(ip, Convert.ToInt32(Port.Text));
                   socketWatch.Bind(point);//绑定端口号
                  ShowMsg("监听成功!");
                   socketWatch.Listen();//设置监听
                  //创建监听线程
                   Thread thread = new Thread(Listen);
                    thread.IsBackground = true;
                    thread.Start(socketWatch);
              }
               catch { }

         }

          void Listen(object o)
           {
                try
                {
                   Socket socketWatch = o as Socket;
                    while (true)
                    {
                       socketSend = socketWatch.Accept();//等待接收客户端连接
                      ShowMsg(socketSend.RemoteEndPoint.ToString() + ":" + "连接成功!");
                      //开启一个新线程，执行接收消息方法
                      Thread r_thread = new Thread(Received);
                       r_thread.IsBackground = true;
                       r_thread.Start(socketSend);
                   }
               }
               catch { }
          }

          /// <summary>
            /// 服务器端不停的接收客户端发来的消息
           /// </summary>
            /// <param name="o"></param>
            void Received(object o)
            {
               try
               {
                    Socket socketSend = o as Socket;
                   while (true)
                    {
                        //客户端连接服务器成功后，服务器接收客户端发送的消息
                     byte[] buffer = new byte[ *  * ];
                        //实际接收到的有效字节数
                       int len = socketSend.Receive(buffer);
                        if (len == )
                        {
                            break;
                        }
                        string str = Encoding.UTF8.GetString(buffer, , len);
                        ShowMsg("接收到的客户端数据：" + socketSend.RemoteEndPoint + ":" + str);
                    }
                }
                catch { }
            }
            /// <summary>
            /// 服务器向客户端发送消息
           /// </summary>
            /// <param name="str"></param>
            void Send(string str)
               {
                   byte[] buffer = Encoding.UTF8.GetBytes(str);
                   socketSend.Send(buffer);
               }

           void ShowMsg(string msg)
           {
              Dispatcher.Invoke(() => { ListConnet.Items.Add(msg + "\r\n"); });
           }

         private void Send_Click(object sender, RoutedEventArgs e)
         {
              Send(SentConnet.Text.Trim());
          }

         private void Window_Loaded(object sender, RoutedEventArgs e)
          {
          }
          private void Stop_Click(object sender, RoutedEventArgs e)
          {
              socketSend.Close();
              ShowMsg("已经停止监听!");
          }
      }
  }

客户端前台XMAL

 <Window x:Class="Socket_Client.MainWindow"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
          xmlns:local="clr-namespace:Socket_Client"
          mc:Ignorable="d"
          Title="客户端" Height="350" Width="525">
     <Grid>
          <Grid.RowDefinitions>
              <RowDefinition Height="50*"/>
              <RowDefinition Height="190*"/>
              <RowDefinition Height="81*"/>
          </Grid.RowDefinitions>
          <Grid Grid.Row="0">
              <WrapPanel VerticalAlignment="Center">
                  <Label Padding="5">IP:</Label>
                  <TextBox Padding="3" Width="150" Name="IP"></TextBox>
                  <Label Padding="5">Port:</Label>
                  <TextBox Padding="3" Width="100" Name="Port"></TextBox>
                  <Button Padding="3" Margin="3" Click="Start_View_Click">连接</Button>
                  <Button Padding="3" Margin="3" Click="Stop_Click">断开连接</Button>
              </WrapPanel>
          </Grid>
          <Grid Grid.Row="1">
              <TextBox Name="ListConnet"></TextBox>
          </Grid>
          <Grid Grid.Row="2">
              <Grid.ColumnDefinitions>
                  <ColumnDefinition Width="405*"/>
                  <ColumnDefinition Width="113*"/>
              </Grid.ColumnDefinitions>

             <TextBox Name="SentConnet"></TextBox>
              <Button Grid.Column="1" Click="Send_Click">发送</Button>

         </Grid>
      </Grid>
  </Window>

客户端后台代码

 using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Net;
  using System.Net.Sockets;
  using System.Text;
  using System.Threading;
  using System.Threading.Tasks;
  using System.Windows;
  using System.Windows.Controls;
  using System.Windows.Data;
  using System.Windows.Documents;
  using System.Windows.Input;
  using System.Windows.Media;
  using System.Windows.Media.Imaging;
  using System.Windows.Navigation;
  using System.Windows.Shapes;

 namespace Socket_Client
  {
      /// <summary>
      /// MainWindow.xaml 的交互逻辑
     /// </summary>
      public partial class MainWindow : Window
      {
          public MainWindow()
          {
              InitializeComponent();
          }
          Socket socketSend;

         private void Start_View_Click(object sender, RoutedEventArgs e)
          {
              try
                {
                                  //创建客户端Socket，获得远程ip和端口号
                     socketSend = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                      IPAddress ip = IPAddress.Parse(IP.Text);
                      IPEndPoint point = new IPEndPoint(ip, Convert.ToInt32(Port.Text));

                      socketSend.Connect(point);
                      ShowMsg("连接成功!");
                                   //开启新的线程，不停的接收服务器发来的消息
                     Thread c_thread = new Thread(Received);
                      c_thread.IsBackground = true;
                      c_thread.Start();
                 }
               catch (Exception)
              {
                 ShowMsg("IP或者端口号错误...");
              }

         }
          void ShowMsg(string str)
           {

             Dispatcher.Invoke(() => { ListConnet.AppendText(str + "\r\n"); });
          }
          /// <summary>
           /// 接收服务端返回的消息
          /// </summary>
          void Received()
          {
              while (true)
              {
                try
                {
                     byte[] buffer = new byte[ *  * ];
                     //实际接收到的有效字节数
                     int len = socketSend.Receive(buffer);
                     if (len == )
                     {
                         continue;
                       }
                      string str = Encoding.UTF8.GetString(buffer, , len);
                      ShowMsg("接收到的服务端数据：" + socketSend.RemoteEndPoint + ":" + str);
                  }
                  catch
                  {

                 }
             }
          }

         private void Send_Click(object sender, RoutedEventArgs e)
          {
              try
              {
                       string msg = SentConnet.Text.Trim();
                       byte[] buffer = new byte[ *  * ];
                       buffer = Encoding.UTF8.GetBytes(msg);
                       socketSend.Send(buffer);
                }
              catch { }

         }

         private void Stop_Click(object sender, RoutedEventArgs e)
          {
              socketSend.Close();
              ShowMsg("连接已经断开!");
          }
      }
  }

运行结果