UdpClient.() vs UdpClient(端口)

Question

我有一个小问题和一个解决方案，但我想知道到底发生了什么。根据UdpClient的构造函数，我使用EndReceive()抛出套接字异常( 10054 -现有连接被远程主机关闭(从德语翻译过来))

谢谢你的任何提示！文森

private UdpClient udpClient;

    void recv(IAsyncResult res)
    {
        IPEndPoint remote = new IPEndPoint(IPAddress.Any, 0);
        byte[] data = udpClient.EndReceive(res, ref remote); // code stops here in debug

        // do something with data received from remote

        udpClient.BeginReceive(new AsyncCallback(recv), null);
    }

    private void Form1_Load(object sender, EventArgs e)
    {

        //udpClient = new UdpClient(); // will throw exception
        udpClient = new UdpClient(8000); // will not throw exception
        udpClient.Connect("127.0.0.1", 8000);
        udpClient.BeginReceive(new AsyncCallback(recv), null);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        udpClient.Send(Encoding.ASCII.GetBytes("Hallo"), 5);
    }

Answer 1

案例1: udpClient =新的UdpClient() -您将套接字绑定到随机本地端口

案例2: udpClient =新的UdpClient( 8000 ) -您将套接字绑定到本地端口8000

也许在第一种情况下，远程主机尝试发送到随机端口并被防火墙拒绝？