C# C语言中的聊天应用

我已经尝试了这段代码来制作聊天应用程序。当我运行应用程序时，我遇到了一个异常：发送或接收数据的请求被禁止，因为套接字未连接，并且在使用sendto调用发送数据报套接字时，没有提供地址

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您创建了套接字，但在创建后没有将其绑定到端口。当您想要发送数据时，可以绑定它

仅当您希望发送数据时绑定是不正确的行为

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您还只需将套接字绑定到本地IPEndpoint。使用此功能发送数据报时，将使用远程IPEndpoint。

使用套接字包括以下基本步骤：

创建套接字

绑定到网络接口 监听连接或进行套接字连接 拨打收发电话 完成前三个步骤后，将建立套接字连接，您需要使用该连接进行发送和接收系统调用。这意味着，前三个列出的点仅执行一次，您将使用它进行任意次数的发送和接收调用，直到连接最终关闭

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将进一步帮助您..

那么，您的问题是什么？我的问题是如何删除我遇到的异常？谢谢，您能告诉我为了使代码正常工作，我必须对代码进行哪些修改吗。我是新手。谢谢。请告诉我，为了让代码正常工作，我必须在程序中进行哪些更正。

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


namespace client_chatApplication
{
    public partial class Form1 : Form
    {
        Socket sck;
        EndPoint epLocal, epRemote;
        public Form1()
        {
            InitializeComponent();
            sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            sck.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
            textLocalIP.Text = GetLocalIp();
            textFriendsIP.Text = GetLocalIp();
        }

        //to get the local ip address
        private string GetLocalIp()
        {
            IPHostEntry host;
            host = Dns.GetHostEntry(Dns.GetHostName());
            foreach (IPAddress ip in host.AddressList)
            {
                if (ip.AddressFamily == AddressFamily.InterNetwork)
                {
                    return ip.ToString();
                }
            }
            return "127.0.0.1";
        }

        public void MessageCallBack(IAsyncResult aresult)
        {
            try
            {
                int size = sck.EndReceiveFrom(aresult, ref epRemote);
                if (size > 0)
                {
                    byte[] receivedData = new byte[1464];

                    receivedData = (byte[])aresult.AsyncState;
                    ASCIIEncoding eEncoding = new ASCIIEncoding();
                    string receivedMessage = eEncoding.GetString(receivedData);
                    listMessage.Items.Add("fiend" + receivedMessage);
                }
                byte[] buffer = new byte[1500];
                sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);
            }
            catch (Exception exp)
            {
                MessageBox.Show(exp.ToString());

            }
        }
        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void textLocalIP_TextChanged(object sender, EventArgs e)
        {
            try
            {

                System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
                byte[] msg = new byte[1500];
                msg = enc.GetBytes(textMessage.Text);
                sck.Send(msg);
                listMessage.Items.Add("yoy" + textMessage.Text);
                textMessage.Clear();

            }
            catch (Exception exp)
            {
                MessageBox.Show(exp.ToString());
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                epLocal = new IPEndPoint(IPAddress.Parse(textLocalIP.Text), Convert.ToInt32(textLocalPort.Text));
                sck.Bind(epLocal);

                epRemote = new IPEndPoint(IPAddress.Parse(textFriendsIP.Text), Convert.ToInt32(textFriendsPort.Text));
                sck.Bind(epRemote);

                byte[] buffer = new byte[1500];
                Socket dataSocket = AsyncSocket.EndAccept(_IAsyncResult);
                sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);
                button1.Text = "connected";
                button1.Enabled = false;
                button2.Enabled = true;
                textMessage.Focus();
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());

            }
        }
    }
}