C# Socket通信DEMO

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

1.服务端前台XMAL

<Window x:Class="WPFAPP.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:WPFAPP"
         mc:Ignorable="d"
         Title="服务端" Height="350" Width="525" Loaded="Window_Loaded" >
    <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">开始监听</Button>
                <Button Padding="3" Margin="3" Click="Stop_Click">停止监听</Button>
            </WrapPanel>
        </Grid>
        <Grid Grid.Row="1">
            <ListBox Name="ListConnet"></ListBox>
        </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>

2.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 WPFAPP
{
    /// <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(10);//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[1024 * 1024 * 3];
                    //实际接收到的有效字节数
                    int len = socketSend.Receive(buffer);
                    if (len == 0)
                    {
                        break;
                    }
                    string str = Encoding.UTF8.GetString(buffer, 0, 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 + "
"); });
        }
        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!");
        }
    }
}

3.客户端前台XMAL

<Window x:Class="WPFClient.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:WPFClient"
         mc:Ignorable="d"
         Title="客户端" Height="350" Width="525">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="50*"/>
            <RowDefinition Height="50*"/>
            <RowDefinition Height="200
                           *"/>
        </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>

4.客户端后台代码

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

namespace WPFClient
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.IP.Text = "127.0.0.1";
            this.Port.Text = "5000";
            this.SentConnet.Text= @"发送消息";
        }
        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 + "
"); });
        }
        /// <summary>
        /// 接收服务端返回的消息
        /// </summary>
        void Received()
        {
            while (true)
            {
                try
                {
                    byte[] buffer = new byte[1024 * 1024 * 3];
                    //实际接收到的有效字节数
                    int len = socketSend.Receive(buffer);
                    if (len == 0)
                    {
                        continue;
                    }
                    string str = Encoding.UTF8.GetString(buffer, 0, 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[1024 * 1024 * 3];
                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!");
        }
    }
}