C#客户端为什么连接不上服务器，当ip地址为127.0.0.1是没有问题的

服务端Server
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 Server
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private void textBox2_TextChanged(object sender, EventArgs e)
    {

    }
    /// <summary>
    /// 开始监听
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    /// 
    Socket socketSend;
    private void btnStart_Click(object sender, EventArgs e)
    {
        try 
        {
            //当点击开始监听时，创建一个负责监听IP地址和端口号的Socket
            Socket socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //创建ip对象
            IPAddress ip=IPAddress.Any;//IpAddress.Parse(txtServer.Text);
            //创建端口对象
            IPEndPoint point=new IPEndPoint(ip,Convert.ToInt32(txtPort.Text));
            //监听端口
            socketWatch.Bind(point);
            ShowMsg("启动成功");
            btnStart.Enabled = false;//按钮只能按一次
            //表示每次只能容纳10个，不代表总容量为10
            socketWatch.Listen(10);
            ////等待客户端连接Accept,并且返回一个负责通信的Socket
            //Socket socketSend=socketWatch.Accept();
            ////socketSend.RemoteEndPoint--返回连接客户端的IP地址
            //ShowMsg(socketSend.RemoteEndPoint.ToString()+":连接成功");

            //创建线程接收Listen函数
            Thread th = new Thread(Listen);
            th.IsBackground = true;
            th.Start(socketWatch);
        }
        catch { }
    }
    //将连接的客户端的ip地址和SocketSend存入 键值对集合中
    Dictionary<string, Socket> dicSocket = new Dictionary<string, Socket>();
    /// <summary>
    /// 等待客户端的 连接，并且创建一个与之通信的Socket
    /// </summary>
    /// <param name="obj"></param>
    void Listen(object obj)
    {
        Socket socketWatch = obj as Socket;//as做类型转换，如果返回的是Socket对象就是返回他，不是就返回null
       //用循环，一直等待客户端连接
        while (true)
        {
            try 
            { 
                //等待客户端连接Accept,并且返回一个负责通信的Socket
                socketSend = socketWatch.Accept();

                //将连接的客户端的ip地址和SocketSend存入 键值对集合中
                dicSocket.Add(socketSend.RemoteEndPoint.ToString(),socketSend);
                //客户端的ip地址存入下拉框
                cboUser.Items.Add(socketSend.RemoteEndPoint.ToString());
                //socketSend.RemoteEndPoint--返回连接客户端的IP地址
                ShowMsg(socketSend.RemoteEndPoint.ToString() + ":连接成功");
                //下拉框默认选中第一个
                cboUser.SelectedIndex = 0;

                //开启一个新线程来接收客户端发过来的消息
                Thread th = new Thread(Receive);
                th.IsBackground = true;
                th.Start(socketSend);
            }
            catch { }

        }
    }
    /// <summary>
    /// 不停的接收客户端发过来的消息
    /// </summary>
    /// <param name="obj"></param>
    void Receive(object obj)
    {
        Socket socketSend = obj as Socket;
        while (true)
        {
            try 
            { 
                //接收客户端发过来的消息
                byte[] buffer = new byte[1024 * 1024 * 2];
                //实际接收的数据r
                int r = socketSend.Receive(buffer);
                if (r == 0)
                {
                    //当r为0的时候表示用户下线,跳出接收循环
                    ShowMsg(socketSend.RemoteEndPoint.ToString() + ":" + "已经下线");
                    break;
                }
                //将字节转换为字符
                string msg = Encoding.UTF8.GetString(buffer, 0, r);
                ShowMsg(socketSend.RemoteEndPoint.ToString() + ":" + msg);


                //将客户端的消息发回去
                SendMsg(msg);
            }
            catch { }
        }
    }
    /// <summary>
    /// 服务器向客户端发信息
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void button4_Click(object sender, EventArgs e)
    {
        try
        {
            string msg = txtSend.Text.Trim();
            //打印到自己的控制台中
            ShowMsg("服务器："+msg);
            //将消息发给对方
            SendMsg(msg);
        }
        catch { }
    }
    /// <summary>
    /// 服务器向客户端发信息
    /// </summary>
    void SendMsg(string msg)
    {
        byte[] buffer = System.Text.Encoding.UTF8.GetBytes(msg);
        List<byte> list = new List<byte>();
        list.Add(0);//表示发送的是文字
        list.AddRange(buffer);
        byte[] newBuffer = list.ToArray();
        //buffer=list.toArray()//不能这样赋值，因为长度不一
        //获得用户下拉框选中的ip地址
        //cboUser.SelectedIndex = 0;
        string ip = cboUser.SelectedItem.ToString();
        dicSocket[ip].Send(newBuffer);
        //socketSend.Send(buffer);
        txtSend.Text = ""; //清空发送栏
    }
    /// <summary>
    /// 打印文字到TextBox中
    /// </summary>
    /// <param name="str"></param>
    void ShowMsg(string str)
    {
        //之所以不是Text，防止覆盖
        txtLog.AppendText(str + "\r\n");
    }
    /// <summary>
    /// 程序加载就取消跨线程访问
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void Form1_Load(object sender, EventArgs e)
    {
        Control.CheckForIllegalCrossThreadCalls = false;
    }
    /// <summary>
    /// 选择发送的文件
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void button2_Click(object sender, EventArgs e)
    {
        try
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Title = "请选择你要发送的文件";
            ofd.Filter = "文件文件|*.txt|图片文件|*.jpg|全部文件|*.*";
            ofd.InitialDirectory = @"C:\Users\Administrator\Desktop";
            ofd.ShowDialog();
            string path = ofd.FileName;
            txtPath.Text = path;//Path.GetFileName(path);
        }
        catch { }
    }
    /// <summary>
    /// 发送文件
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void button3_Click(object sender, EventArgs e)
    {
        try
        {
            //获得发送文件的路径
            string path = txtPath.Text;
            if (path == "")
            {
                return;
            }
            using (FileStream fsRead = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read))
            {
                byte[] buffer = new byte[1024 * 1024 * 100];
                int r = fsRead.Read(buffer, 0, buffer.Length);
                List<byte> listFile = new List<byte>();
                listFile.Add(1);//1表示发送的是文件
                listFile.AddRange(buffer);
                byte[] newBuffer = listFile.ToArray();
                dicSocket[cboUser.SelectedItem.ToString()].Send(newBuffer, 0, r+1, SocketFlags.None);
            }
        }
        catch { }
    }

    private void button5_Click(object sender, EventArgs e)
    {
        try
        {
            byte[] buffer = new byte[1];
            buffer[0] = 2;
            dicSocket[cboUser.SelectedItem.ToString()].Send(buffer);
        }
        catch { }

    }

    private void cboUser_SelectedIndexChanged(object sender, EventArgs e)
    {

    }
}

}

不论是WIN7还是WIN10防火墙默认都是开的，除非你用的是网吧那种光盘做的系统，百度一下，如何windows添加端口访问规则

另外一台电脑 telnet 192.168.X.XXX port，估计是无法连接，百度防火墙吧

客户端Client
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 Client
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    Socket socketSend;
    private void btnConnect_Click(object sender, EventArgs e)
    {
        try
        {
            //创建负责通信的Socket通信
            socketSend = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPAddress ip = IPAddress.Parse(txtIp.Text);
            IPEndPoint point = new IPEndPoint(ip, Convert.ToInt32(txtPort.Text));
            ///服务器没有连接会抛异常
            //连接 ---获得要连接服务器的IP地址和端口
            socketSend.Connect(point);
            ShowMsg("连接成功");
            btnConnect.Enabled = false;
            //开启一个新的线程接收客户端发过的消息
            Thread th = new Thread(Receive);
            th.IsBackground = true;
            th.Start();
        }
        catch { }
    }
    /// <summary>
    /// 把消息显示到txtlog中
    /// </summary>
    /// <param name="str"></param>
    void ShowMsg(string str)
    {
        txtLog.AppendText(str+"\r\n");
    }
    /// <summary>
    /// 客户端给服务端发送信息
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnSend_Click(object sender, EventArgs e)
    {
        try 
        {
            string msg = txtSend.Text.Trim();
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(msg);
            socketSend.Send(buffer);
            //程序关闭应该提示下线
            txtSend.Text = "";//清空发送栏
        }
        catch { }
    }
    /// <summary>
    /// 不停的接收服务器发过来的消息
    /// </summary>
    void Receive()
    {
        while (true)
        {
            try 
            {
                byte[] buffer = new byte[1024 * 1024 * 100];
                int r = socketSend.Receive(buffer);
                if (r == 0)
                {
                    break;
                }
                //判断 0表示的是发送文字消息，1表示文件，2表示震动
                if (buffer[0] == 0)
                {
                    string msg = Encoding.UTF8.GetString(buffer, 1, r-1);//(buffer, 0, r);
                    //判断是谁发过来的消息
                    string UserName = socketSend.RemoteEndPoint.ToString();
                    if (UserName == socketSend.RemoteEndPoint.ToString())
                    {

                    }

                    ShowMsg(UserName + ":" + msg);

                }
                else if (buffer[0] == 1)
                {
                    try
                    {
                        SaveFileDialog sfd = new SaveFileDialog();
                        sfd.Title = "请选择保存的路径";
                        sfd.Filter = "文本文件|*.txt|图片文件|*.jpg|全部文件|*.*";
                        sfd.InitialDirectory = @"C:\Users\Administrator\Desktop";
                        sfd.ShowDialog(this);
                        //sfd.FileName表示接受过来的文件的路径-- 将接受的文件保存到桌面
                        string path = sfd.FileName;//@"C:\Users\Administrator\Desktop";//sfd.fileName
                        if (path == "")
                        {
                            return;
                        }
                        using (FileStream fsWrite = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
                        {
                            fsWrite.Write(buffer, 1, r - 1);
                        }
                        MessageBox.Show("保存成功");
                    }
                    catch{ }

                }
                else if (buffer[0] == 2)
                {
                    ZhenDong();
                }
            }
            catch { }
        }
    }
    /// <summary>
    /// 震动
    /// </summary>
    void ZhenDong()
    {
        for (int i = 0; i < 500; i++)
        {
            this.Location = new Point(400,100);
            this.Location = new Point(180,180);
        }
    }
    private void Form1_Load(object sender, EventArgs e)
    {
        Control.CheckForIllegalCrossThreadCalls = false;

    }