C#中使用UdpClient类进行简单通信的例子

/// <summary>
/// 客户端
/// </summary>
class UDPSender
{
    static void Main(string[] args)
    {
        //创建一个UdpClient对象，0表示系统自动分配发送端口
        UdpClient udpSender = new UdpClient(0);
            
        //连接到服务端指定端口
        udpSender.Connect("localhost", 11000);
            
        //把消息转换成字节流发送到服务端
        byte[] sendBytes = Encoding.ASCII.GetBytes("Is anybody there?");
        udpSender.Send(sendBytes, sendBytes.Length);
            
        //关闭链接
        udpSender.Close();
    }
}

/// <summary>
/// 服务端
/// </summary>
class UDPReceive
{
    static void Main(string[] args)
    {
        //创建一个UdpClient对象，11000为接收端口
        UdpClient udpReceive = new UdpClient(11000);

        //设置远程主机，(IPAddress.Any, 0)代表接收所有IP所有端口发送的数据
        IPEndPoint remoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);//或IPEndPoint remoteIpEndPoint = null;

        //监听数据，接收到数据后，把数据转换成字符串并输出
        byte[] receiveBytes = udpReceive.Receive(ref remoteIpEndPoint);
        string returnData = Encoding.ASCII.GetString(receiveBytes);
        Console.WriteLine("This is the message you received " + returnData.ToString());
        Console.WriteLine("This message was sent from " + remoteIpEndPoint.Address.ToString() + " on their port number " + remoteIpEndPoint.Port.ToString());
            
        //关闭连接
        udpReceive.Close();
    }
}