使用UdpClient，如何在UdpClient.Connect()成功之前重试它？

Question

我的客户机/服务器程序彼此很好地工作，但只有当服务器在我的客户端启动之前启动并运行时才能正常工作。如果客户端在第一次尝试时未能连接，我无法让它再次尝试。

这是我客户的connect方法。

public void connect()
    {          
        IPAddress server_address = IPAddress.Parse("127.0.0.1");
        IPEndPoint server_ip = new IPEndPoint(server_address, 5685);
        Console.WriteLine("2");
        bool connected = false;
        while (!connected)
        {
            try
            {
                Console.WriteLine("IN CONNECTED");
                udp_client.Connect(server_ip);
                byte[] send_data = Encoding.ASCII.GetBytes("INIT");
                udp_client.Send(send_data, send_data.Length);
                byte[] received_bytes = udp_client.Receive(ref server_ip);
                string received_data = Encoding.ASCII.GetString(received_bytes);
                if (received_data == "INIT")
                {
                    connected = true;
                    Console.WriteLine("RECEIVED INIT");
                    listen(server_ip);
                }

            }

            catch (Exception e)
            {
                Console.WriteLine(e);
            }
        }
    }

我希望看到的是udp_client.Connect(server_ip)循环，直到我收到来自服务器的"INIT“消息。

按照目前的情况，不存在循环。它似乎被困在udp_client.Receive(ref server_ip)上了。

任何帮助都将不胜感激！

Answer 1

这是pseudoCode --您必须将一些东西移到类范围以允许将来的发送/接收(您将使用不同的方法)。这只是为了向您展示如何在连接阻塞时进行连接：

bool isClientConnected = false;
var connector = new System.ComponentModel.BackgroundWorker();

public void connectToUDP(){
    connector.DoWork+= connect;
    connector.RunWorkerAsync();
} 

 private void connect(object sender, DoWorkEventArgs e)
{          
    IPAddress server_address = IPAddress.Parse("127.0.0.1");
    IPEndPoint server_ip = new IPEndPoint(server_address, 5685);
    Console.WriteLine("2");

                try
        {
            Console.WriteLine("Waiting for server...");
            udp_client.Connect(server_ip);
            byte[] send_data = Encoding.ASCII.GetBytes("INIT");
            udp_client.Send(send_data, send_data.Length);
            byte[] received_bytes = udp_client.Receive(ref server_ip);
            string received_data = Encoding.ASCII.GetString(received_bytes);
            if (received_data == "INIT")
            {
                isClietConnected = true;
                Console.WriteLine("now connected");
                listen(server_ip);
            }


        catch (Exception e)
        {
            Console.WriteLine(e);
        }

}
public bool sendReceiveUDP(string send){
     if(!isClientConnected){
          return false;
     }
     //perform send
     return true;
 }

然后使用类作用域维护连接的会话，并使用不同的方法发送/接收。这只是为了连接，因为你只需要做一次。

你如何设置这样的东西：

  private bool isConnected = false();
  private bool send(){
      if(!isConnected){
           connect();
      }
      //send
  }
  private bool connect(){
      if(!isConnected){
          //launch connection thread
      }
   }
  private delegate void onNewReceive(string message);
  public event onNewReceive onNewReceiveEvent;
  public void fireEvent(string message){
         onNewReceiveEvent.Invoke(message);
  }
       private void waitForData(object sender, DoWorkEventArgs e){
     //this is the backgroundworker
     while(true){
     receive();
     fireEvent(message);
     }
  }

然后，在另一个类中订阅onNewREceivedEvent并处理入站消息。onNewReceivedEvent += processInboundMEsasage()；

这些都是psuedocode和“脑编译”(对其他人来说是creit)，所以它只用于演示。没有智慧，我就迷失了。