C# socket网络编程(发消息示例)

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace SocketServer
{
    public partial class Form1 : Form
    {
        Socket server;
        Socket accept;
        public Form1()
        {
            InitializeComponent();
        }

        private void btnBind_Click(object sender, EventArgs e)
        {
            Button btn = sender as Button;
            if (btn.Text == "Bind")
            {
                //绑定，启动异步接受连接
                try
                {
                    int port = int.Parse(tbPort.Text);
                    IPAddress ipaddress = IPAddress.Parse(tbIP.Text);
                    IPEndPoint endpoint = new IPEndPoint(ipaddress, port);
                    server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

                    server.Bind(endpoint);
                    server.Listen(10);
                    server.BeginAccept(AcceptCallback, server);
                    btn.Text = "Close";
                }
                catch
                { }
            }
            else if (btn.Text == "Close")
            {
                server.Close();
                btn.Text = "Bind";
            }
        }
        private void AcceptCallback(IAsyncResult ar)
        {
            Socket sock = ar.AsyncState as Socket;
            try
            {
                accept = sock.EndAccept(ar);
                //得到连接套接字accept
                StateObject so = new StateObject(accept);
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText("\t收到连接："   so.endpoint   "\n");
                }));

                accept.BeginReceive(so.buffer, 0, so.buffer.Length, SocketFlags.None, ReceiveCallback, so);
                server.BeginAccept(AcceptCallback, server);
            }
            catch (SocketException)
            {
                //试图访问套接字时发生错误
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText("\t连接断开：(\n");
                }));
            }
            catch (ObjectDisposedException)
            {
                //Socket 对象已关闭。
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText("\t套接字已关闭：(\n");
                }));
            }
            
        }
        private void ReceiveCallback(IAsyncResult ar)
        {
            StateObject so = ar.AsyncState as StateObject;
            try
            {
                int length = so.sock.EndReceive(ar);
                string recvstr = System.Text.Encoding.UTF8.GetString(so.buffer, 0, length);
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText(so.endpoint   ":"   recvstr    "\n");
                }));
                so.buffer = new byte[1024];
                so.sock.BeginReceive(so.buffer, 0, so.buffer.Length, SocketFlags.None, ReceiveCallback, so);
            }
            catch (SocketException)
            {
                //连接断开
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText("\t连接断开\n");
                }));
                accept = null;
            }
            catch (ObjectDisposedException)
            {
                //套接字已经关闭
                this.BeginInvoke(new ThreadStart(() =>
                {
                    this.tbMsg.AppendText("\t套接字已关闭\n");
                }));
            }
            
        }

        private void btnSend_Click(object sender, EventArgs e)
        {
            if (server != null)
            {
                byte[] sendbytes = System.Text.Encoding.UTF8.GetBytes(this.tbMsgSend.Text);
                accept.Send(sendbytes);
                this.tbMsg.AppendText("我："   this.tbMsgSend.Text   "\n");
                this.tbMsgSend.Clear();
            }
        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            this.tbMsg.Clear();
        }

        
    }
    public class StateObject
    {
        public byte[] buffer = new byte[1024];
        public Socket sock = null;
        public string endpoint;
        public StateObject(Socket sock)
        {
            this.sock = sock;
            endpoint = sock.RemoteEndPoint.ToString();
        }
    }
}