C# Udp监听和socket发送（转载）

原文地址：https://blog.csdn.net/anxin591025/article/details/11898241

定义一个类

class Class1
    {
        public const int port = 11000;
        public void StarListener()
        {
            UdpClient udpclient = new UdpClient(port);
            IPEndPoint ipendpoint = new IPEndPoint(IPAddress.Any, port);
            try
            {
                while (true)
                {
                    byte[] bytes = udpclient.Receive(ref ipendpoint);
                    string strIP = "信息来自"+ ipendpoint.Address.ToString();
                    string strInfo = Encoding.GetEncoding("gb2312").GetString(bytes, 0, bytes.Length);
                    MessageBox.Show(strInfo, strIP);
                }
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString());
            }
            finally
            {
                socket.Close();
            }
        }
        public string Send(string strServer, string strContent)
        {
            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            IPAddress ipaddress = IPAddress.Parse(strServer);
            byte[] btContent = Encoding.GetEncoding("gb2312").GetBytes(strContent);
            IPEndPoint ipendpoint = new IPEndPoint(ipaddress, port);
            socket.SendTo(btContent, ipendpoint);
            socket.Close();
            return "发送成功！";
        }

服务端监听

            Class1 class1 = new Class1();
            class1.StarListener();

客户端发送

        //textBox1是IP地址栏，textBox2是要发送的信息，button1发送按钮
        Class1 class1 = new Class1();
        System.Diagnostics.Process myProcess;
        
        private void Form2_Load(object sender, EventArgs e)
        {
            myProcess = System.Diagnostics.Process.Start("Server.exe");//开启服务
            richTextBox1.Text = string.Empty;
            richTextBox1.Focus();
        }
 
        private void button1_Click(object sender, EventArgs e)//发送按钮
        {
            MessageBox.Show(class1.Send(textBox1.Text, richTextBox1.Text));
        }
 
        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 13)//按下Enter的时候
                richTextBox1.Focus();
        }
 
        private void richTextBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 13)//按下Enter的时候
                button1.Focus();
        }
 
        private void Form2_FormClosing(object sender, FormClosingEventArgs e)
        {
            myProcess.Kill();//关闭服务
        }