c# - UdpClient.() 与 UdpClient(端口)

Question

我有一个小问题和一个解决方案，但我想了解到底发生了什么。根据 UdpClient 的构造函数，我使用 EndReceive() 是否抛出套接字异常(10054 - 现有连接已被远程主机关闭(翻译自德语))

感谢任何提示!文森特

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

情况 1:udpClient = new UdpClient() - 您将套接字绑定(bind)到随机本地端口
情况 2:udpClient = new UdpClient(8000) - 您将套接字绑定(bind)到本地端口 8000

也许万一远程主机尝试发送到随机端口并被防火墙拒绝？