上網自學了一點C# 但不是很理解
我想用C#做一個Server 和 Clinet
用別人的範例可以做到同網段下通信, 但要是網段不同就連不上了, 網路上搜尋到使用UPnp來解決
參考網站
https://blog.csdn.net/yangyifan0/article/details/52295253
不曉得哪裡寫錯了, 想請問要怎麼修改能解決不同網段可以通信的問題呢

Server端程式碼

IPAddress ipv4;
String eip;
int iport = 8733;
int eport = 8733;
static Socket socketListener;

public Form1()
{
    InitializeComponent();

    String name = Dns.GetHostName();
    ipv4 = Dns.GetHostEntry(name).AddressList.Where(i => i.AddressFamily == AddressFamily.InterNetwork).FirstOrDefault();

    WebClient webClient = new WebClient();
    HttpClient client = new HttpClient();
    String rawRes = webClient.DownloadString("http://checkip.dyndns.org/");
    String regex = @"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b";
    eip = Regex.Match(rawRes, regex).Value;
    
    OpenUPnp();
    ServerEnd(eport, 10);
    Thread th = new Thread(ServerCommunity);
    th.Start(socketListener);
}

 private Boolean OpenUPnp()
 {
     UPnPNAT uPnPNAT = new UPnPNAT();

     IStaticPortMappingCollection mapping = uPnPNAT.StaticPortMappingCollection;
     if (mapping == null)
     {
         return false;
     }
     mapping.Add(eport, "TCP", iport, ipv4.ToString(), true, "測試");
     socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
     socket.Bind(new IPEndPoint(ipv4, iport));
     IList<ServicePoint> servicePoints = new List<ServicePoint>();
     return true;
 }
 
 private static void ServerCommunity(object obListener)
{
    Socket temp = (Socket)obListener;
    while (true)
    {
        Socket socketSender = temp.Accept();
        logd("ServerCommunity()", ("Client IP = " + socketSender.RemoteEndPoint.ToString()) + " Connect Succese!");
        Thread ReceiveMsg = new Thread(ReceiveClient);
        ReceiveMsg.IsBackground = true;
        Thread SendToClient = new Thread(SendMsgToClient);
        SendToClient.Start(socketSender);
        ReceiveMsg.Start(socketSender);
    }
}

Client端程式碼

IPAddress ipv4;
String eip;
int iport = 8733;
int eport = 8733;
static Socket socketListener;

public Form1()
{
    InitializeComponent();

    String name = Dns.GetHostName();
    ipv4 = Dns.GetHostEntry(name).AddressList.Where(i => i.AddressFamily == AddressFamily.InterNetwork).FirstOrDefault();

    WebClient webClient = new WebClient();
    HttpClient client = new HttpClient();
    String rawRes = webClient.DownloadString("http://checkip.dyndns.org/");
    String regex = @"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b";
    eip = Regex.Match(rawRes, regex).Value;
    
    ClientSocket(ipv4.ToString(), iport);
}

private static void ClientSocket(string ip, int port)
{
    socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    IPAddress myIp = IPAddress.Parse(ip);
    IPEndPoint point = new IPEndPoint(myIp, port);
    socket.Connect(point);

    logd("ClientSocket(" + ip + ", " + port+")", "Connect Succese! " + socket.RemoteEndPoint.ToString());

    Thread sendMsg = new Thread(SendMsgToServer);
    Thread ReceiveMsg = new Thread(ReceiveMsgFromServer);
    ReceiveMsg.IsBackground = true;
    ReceiveMsg.Start();
    sendMsg.Start();
}

感激不盡