如何在单个ASP.NET页面中侦听套接字

Question

我正在开发使用TCP Socekts和C＃的客户端 - 服务器应用程序。我需要从控制台应用程序发送消息到ASP页面。我可以使用OnLoad事件从ASP页连接，有时在PageLoad事件中，我只能收到几条消息。我有两个问题： 1.如何连续监听服务器套接字和接收消息？
2.如何知道ASP.NET页面何时关闭（由用户）与服务器断开连接？

服务器控制台应用程序：

 static void StartServer() 
    { 
     serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
     IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Any, 1000); 

     serverSocket.Bind(ipEndPoint); 
     serverSocket.Listen(4); 

     ConsoleKeyInfo cki; 
     XmlDocument doc = new XmlDocument(); 

     doc.Load("test.xml"); 
     serverSocket.BeginAccept(new AsyncCallback(OnAccept), null); 

     Console.WriteLine("Server started " + DateTime.Now + Environment.NewLine); 
     Console.WriteLine("Press S to start Data Sharing or ESC key to quit" + Environment.NewLine);    

     do 
     { 
      cki = Console.ReadKey(); 

      if (cki.Key == ConsoleKey.S) 
      {      
       foreach (XmlNode node in doc.DocumentElement.ChildNodes) 
       { 
        try 
        { 
         _client = (ClientInfo)clientList[0]; 
         if (((ClientInfo)clientList[0]).strName == node.Attributes["type"].InnerText) 
         { 
          SendRecord(node.Attributes["type"].InnerText + node.Attributes["value"].InnerText, (ClientInfo)clientList[0]); 
          clientList.Insert(clientList.Count, (ClientInfo)clientList[0]); 
          clientList.RemoveAt(0); 
         } 
        } 

        catch (Exception ex) 
        { 
         Console.WriteLine(ex.message); 
        } 
       } 
       Console.WriteLine("Data sharing finished " + DateTime.Now); 
      } 

     } while (cki.Key != ConsoleKey.Escape); 
    }   

    static void SendRecord(string _msg, ClientInfo client) 
    { 
     Data msgToSend = new Data(); 
     msgToSend.cmdCommand = Command.Message; 
     msgToSend.strMessage = _msg; 
     byte[] byteData = msgToSend.ToByte(); 

     try 
     { 
      client.socket.BeginSend(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(OnSend), _client); 
      Thread.Sleep(3); 
     } 

     catch (Exception ex) 
     { 
      Console.WriteLine(ex.Message); 
     } 
    } 

ASP.NET客户端：

protected void Page_Load(object sender, EventArgs e) 
{   
    if (!IsPostBack) 
     Connect(); 
} 

protected void Page_OnClose(object sender, EventArgs e) 
{ 
    Disconnect(); 
} 

protected void updateEvent(object sender, EventArgs e) 
{ 
    if (msglist.Count > 0) lstRecords.Items.Add(msg); 
    lstRecords.Height = Unit.Percentage(100);  
} 


private void Connect() 
{ 
    Data msgToSend = new Data(); 

    IPAddress ipAddress = IPAddress.Parse("127.0.0.1"); 
    IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 1000); 
    clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 

    msgToSend.strType = strType; 
    msgToSend.strMessage = null; 
    msgToSend.cmdCommand = Command.List; 

    byteData = msgToSend.ToByte(); 

    try 
    { 
     clientSocket.BeginConnect(ipEndPoint, new AsyncCallback(OnConnect), null); 
     clientSocket.BeginSend(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(OnSend), null); 

     byteData = new byte[1024]; 
     clientSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(OnReceive), null); 
    } 

    catch (Exception ex) 
    { 
     lstRecords.Items.Add(ex.Message); 
    } 
} 

服务器应用程序被发送到WinApp和ConsoleApp没有任何问题。但对于ASP页面，我只能正确接收连接消息，有时我只能收到1-2-3消息。我正在使用javascript setInterval("__doPostBack('upDynamicClock', '');", 1000);刷新页面

Answer 1

HTTP是无状态的，ASP.NET WebForms只会试图用viewstate等隐藏这个。只要您在浏览器中看到该页面，该页面就不再活动，并且您的回调将不再被调用。这也在Create web page with live socket based data中解释。

如果您的目标是使用服务器提供的数据更新HTML元素，请参阅SignalR。