C#利用广播实现群发功能

C#利用广播实现群发功能

[csharp] view
plaincopy

using System;  

using System.Collections.Generic;  

using System.ComponentModel;  

using System.Data;  

using System.Drawing;  

using System.Text;  

using System.Windows.Forms;  

//添加的命名空间引用  

using System.Net;  

using System.Net.Sockets;  

using System.Threading;  

namespace BroadcastExample  

{  

    public partial class FormBroacast : Form  

    {  

        delegate void AppendStringCallback(string text);  

        AppendStringCallback appendStringCallback;  

        //使用的接收端口号  

        private int port = 8001;  

        private UdpClient udpClient;  

        public FormBroacast()  

        {  

            InitializeComponent();  

            appendStringCallback = new AppendStringCallback(AppendString);  

        }  

  

        private void FormBroacast_Load(object sender, EventArgs e)  

        {  

            Thread myThread = new Thread(ReceiveData);  

            //将线程设为后台运行  

            myThread.IsBackground = true;  

            myThread.Start();  

        }  

  

        

        /// <summary>  

        /// 在后台运行的接收线程  

        /// </summary>  

        private void ReceiveData()  

        {  

            //在本机指定的端口接收  

            udpClient = new UdpClient(port);  

            IPEndPoint remote = null;  

            //接收从远程主机发送过来的信息；  

            while (true)  

            {  

                try  

                {  

                    //关闭udpClient时此句会产生异常  

                    byte[] bytes = udpClient.Receive(ref remote);  

                    string str = Encoding.UTF8.GetString(bytes, 0, bytes.Length);  

                    AppendString(string.Format("来自{0}：{1}", remote, str));  

                }  

                catch  

                {  

                    //退出循环，结束线程  

                    break;  

                }  

            }  

        }  

  

        /// <summary>  

        /// 发送消息  

        /// </summary>  

        /// <param name="sender"></param>  

        /// <param name="e"></param>  

        private void buttonSend_Click(object sender, EventArgs e)  

        {  

            UdpClient myUdpClient = new UdpClient();  

            try  

            {  

                //让其自动提供子网中的IP广播地址  

                IPEndPoint iep = new IPEndPoint(IPAddress.Broadcast, 8001);  

                //将发送内容转换为字节数组  

                byte[] bytes =Encoding.UTF8.GetBytes(textBox1.Text);  

                //向子网发送信息  

                myUdpClient.Send(bytes, bytes.Length, iep);  

                textBox1.Clear();  

                textBox1.Focus();  

            }  

            catch (Exception err)  

            {  

                MessageBox.Show(err.Message, "发送失败");  

            }  

            finally  

            {  

                myUdpClient.Close();  

            }  

        }  

         

        private void FormBroacast_FormClosing(object sender, FormClosingEventArgs e)  

        {  

            udpClient.Close();  

        }  

  

        private void AppendString(string text)  

        {  

            if (richTextBox1.InvokeRequired == true)  

            {  

                this.Invoke(appendStringCallback, text);  

            }  

            else  

            {  

                richTextBox1.AppendText(text + "\r\n");  

            }  

        }  

    }  

}  

界面设计：