一、0udpClient

控件：

button（打开，关闭，发送），textbox，richTextBox

打开UDP：

UdpClient udp:

namespace _01udpClient
{public partial class Form1 : Form{public Form1(){InitializeComponent();}//打开UdpClient udp;private void button1_Click(object sender, EventArgs e){//1创建udp对象 指定ip地址和端口号udp = new UdpClient(new IPEndPoint(IPAddress.Any, 8080));//2 接收数据startReceive();}void startReceive(){new Thread(() =>{try{while (true){//创建ip接受客户端的ip地址IPEndPoint ip = null;//接收数据 返回字节数组byte[] body =  udp.Receive(ref ip);string s = Encoding.UTF8.GetString(body);BeginInvoke((Action)(() =>{richTextBox1.AppendText(ip.ToString() + ":" + s + "\t\n");}));}}catch{}}).Start();}//关闭private void button2_Click(object sender, EventArgs e){udp.Close();//关闭udp = null;}private void button3_Click(object sender, EventArgs e){byte[] bs = Encoding.UTF8.GetBytes(this.textBox1.Text);//发数据//参数1 字节数组//参数2 字节长度//参数3 目标主机地址//参数4 端口号udp.Send(bs, bs.Length, "192.168.107.71", 8080);}}
}

二、udpClient组播

namespace _02udpClinet组播
{public partial class Form1 : Form{public Form1(){InitializeComponent();}//打开服务器private void button3_Click(object sender, EventArgs e){udp = new UdpClient(new IPEndPoint(IPAddress.Any, 8080));strartReceive();}UdpClient udp;//异步的方式//1 new Thread() 分线程//2 Task.Run() 异步任务//3 async(异步)和await (等待)async void strartReceive(){while (true){//await 跟一个异步的任务// 等待异步结束之后 再去执行//receiveAsync() 异步接收数据UdpReceiveResult body = await udp.ReceiveAsync();// body.RemoteEndPoint 远程终端//body.Buffer 数据字节数组BeginInvoke((Action)(() =>{richTextBox1.AppendText(body.RemoteEndPoint.ToString() + ":" + Encoding.UTF8.GetString(body.Buffer)+"\t\n");}));}}// 加入组播private void button1_Click(object sender, EventArgs e){//Join 加入udp.JoinMulticastGroup(IPAddress.Parse(this.textBox1.Text));//加入组播地址}private void button2_Click(object sender, EventArgs e){//发送消息byte[] bs =  Encoding.UTF8.GetBytes(this.textBox2.Text);udp.Send(bs, bs.Length, this.textBox1.Text, 8080);}}
}