C#_Socket网络编程实现的简单局域网内即时聊天，发送文件，抖动窗口。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
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 kehuduan
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        Dictionary<string,Socket> dicsocket = new Dictionary<string, Socket>();//键值集合，通过键能找到值
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                //创建监听的socket
                Socket socketwatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                //获得ip地址
                IPAddress ip = IPAddress.Any;//Parse(textBox1.Text);
                //创建端口号对象
                IPEndPoint point = new IPEndPoint(ip, Convert.ToInt32(textBox2.Text));
                socketwatch.Bind(point);
                showmsg(DateTime.Now.ToString() + "监听成功");//192.168.1.103:监听成功
                socketwatch.Listen(10);//开始监听。监听队列10人

                //开启新线程解决卡顿
                Thread lis = new Thread(Listen);
                lis.IsBackground = true;
                lis.Start(socketwatch);
            }
            catch
            {
                
            }
        }
        Socket socketsend;
        /// <summary>
        /// 循环等待接入的客户端
        /// </summary>
        /// <param name="o"></param>
        void Listen(object o)
        {
            try
            {
                Socket socketwatch = o as Socket;
                while (true)
                {
                    //负责跟客户端通信的Socket
                    socketsend = socketwatch.Accept();
                    //把连进来的socket存到建值集合和下拉菜单中，实现给指定的客户端发消息
                    dicsocket.Add(socketsend.RemoteEndPoint.ToString(),socketsend);
                    comboBox1.Items.Add(socketsend.RemoteEndPoint.ToString());//socket.remoteendpoint可以显示socket的ip地址和端口号
                    //192.168.1.103：连接成功
                    showmsg(socketsend.RemoteEndPoint.ToString() + ":" + "连接成功");
                    //连接成功后开启新线程接受消息
                    Thread th = new Thread(Recive);
                    th.IsBackground = true;
                    th.Start(socketsend);

                }
            }
            catch { }
           
        }
        /// <summary>
        /// 服务器端循环接收客户端发来的信息
        /// </summary>
        /// <param name="o"></param>
        void Recive(object o)
        {
            while (true)
            {
                try
                {
                    Socket socketsend = o as Socket;
                    byte[] b = new byte[1024 * 1024 * 2];
                    //实际接收到的有效字节
                    int r = socketsend.Receive(b);
                    if (r == 0)
                    {
                        break;
                    }
                    string str = Encoding.UTF8.GetString(b, 0, r);
                    showmsg(socketsend.RemoteEndPoint.ToString() + "说：" + str);
                }
                catch 
                {

                }
            }
        }
        /// <summary>
        /// 往文本框里添加文字的方法
        /// </summary>
        /// <param name="a"></param>
        void showmsg(string a)
        {
            textBox3.AppendText(a+"\r\n"); 
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;
        }
        /// <summary>
        /// 服务器给客户端发文字消息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            try
            {
                List<byte> nb = new List<byte>();
                string str = textBox4.Text.Trim();
                byte[] b = System.Text.Encoding.UTF8.GetBytes(str);
                nb.Add(0);
                nb.AddRange(b);
                byte[] newb = nb.ToArray();
                string ip = comboBox1.SelectedItem.ToString();
                dicsocket[ip].Send(newb);
                //socketsend.Send(b);
                showmsg("我说 ：" + str);
            }
            catch { }
        }
        /// <summary>
        /// 选择要发送的文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd  = new OpenFileDialog();

            ofd.InitialDirectory = @"C:\Documents and Settings\Administrator\桌面";
            ofd.Title = "请选择要发送的文件";
            ofd.Filter = "所有文件|*.*";
            ofd.ShowDialog(this);//加this
            textBox5.Text = ofd.FileName;

        }
        /// <summary>
        /// 向客户端发送文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            try
            {
                string path = textBox5.Text;
                using (FileStream fsread = new FileStream(path, FileMode.Open, FileAccess.Read)) //把文件转换为文件流
                {
                    byte[] b = new byte[1024 * 1024 * 5];//最大5m的文件
                    int r = fsread.Read(b, 0, b.Length);
                    List<byte> nb = new List<byte>();
                    nb.Add(1);//在第一位加上数字，让客户端可以识别服务端的指令
                    nb.AddRange(b);//往集合中添加集合的方法。
                    byte[] newb = nb.ToArray();
                    dicsocket[comboBox1.SelectedItem.ToString()].Send(newb, 0, r + 1, SocketFlags.None);
                }

            }
            catch { }

        }
        /// <summary>
        /// 抖动窗口
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button5_Click(object sender, EventArgs e)//发送消息
        {
            try
            {
                byte[] b = new byte[1];
                b[0] = 2;
                dicsocket[comboBox1.SelectedItem.ToString()].Send(b);
            }
            catch { }

        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
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 kehuduan
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        Socket socketsend;
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                socketsend = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//设置一个socket

                IPAddress ip = IPAddress.Parse(textBox1.Text);//将文本框中的字符串转换成IP地址。
                IPEndPoint point = new IPEndPoint(ip, Convert.ToInt32(textBox2.Text));//创建IPEndpoint对象实例。包含ip地址和端口号
                socketsend.Connect(point);//连接到IPendpoint所在的监听socket
                showmsg("连接成功");
//开启新线程
                Thread th = new Thread(Recive);
                th.IsBackground = true;
                th.Start();
            }
            catch { }

        }
      
        void showmsg(string str)  //在文本框中添加内容
        {
            textBox3.AppendText(str+"\r\n");
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;//取消跨线程使用控件检查。
        }
        void Recive()//接收
        {
            while (true)
            {
                try
                {
                   
                    byte[] b = new byte[1024 * 1024 * 2];
                    //实际接收到的有效字节
                    int r = socketsend.Receive(b);
                    if (r == 0)
                    {
                        break;
                    }
                    if (b[0] == 0)
                    {
                        string str = Encoding.UTF8.GetString(b, 1, r-1);  //从第二个开始截取，因为第一个元素用来判断服务端发过来的指令。
                        showmsg(socketsend.RemoteEndPoint.ToString() + "说：" + str);
                    }
                    else if (b[0] == 1)
                    {
                        SaveFileDialog sfd = new SaveFileDialog();//保存文件对话框
                        sfd.InitialDirectory = @"C:\Documents and Settings\Administrator\桌面";
                        sfd.Title = "对方发送了一个文件，请选择保存的位置";
                        sfd.ShowDialog();

                        string path = sfd.FileName;
                        using (FileStream fswrite = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite))//数据流控制，用来保存文件。
                        {
                            fswrite.Write(b,1,r-1);
                            MessageBox.Show("保存成功");
                        }
                        
                    }
                    else if (b[0] == 2)//如果发来的字节包首个元素的值==2，就振动
                    {
                        ZD();
                    }
                }
                catch
                {

                }
            }
        }

        private void button2_Click(object sender, EventArgs e)//发送消息
        {
            try
            {
                string str = textBox4.Text.Trim();//存下文本框中的内容
                byte[] b = System.Text.Encoding.UTF8.GetBytes(str);//将内容转换成二进制流（utf8编码）
                socketsend.Send(b);//发送给服务端
                showmsg("我说 ：" + str);//将我说的话放到文本框中
            }
            catch { }
        }
        /// <summary>
        /// 震动窗体
        /// </summary>
        void ZD()//连续修改窗口的Location，模拟抖动窗口效果
        {
            for (int i = 0; i < 50; i++)
            {

                Point a = this.Location;
                a.X += 5;
                a.Y += 5;
                this.Location = a;
                Thread.Sleep(2);
                a.X -=5;
                a.Y -=5;
                this.Location = a;
            }
        }
    }
}