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C# 在套接字连接期间，相同的代码在Windows窗体和Windows服务中产生不同的结果

c# winforms sockets windows-services

C# 在套接字连接期间，相同的代码在Windows窗体和Windows服务中产生不同的结果,c#,winforms,sockets,windows-services,C#,Winforms,Sockets,Windows Services,我有一个充当套接字侦听器（服务器端）的代码，我在WinForms和Windows服务中实现它。里面的一切都是一样的，只是我将Windows服务OnStart和OnStop的实现改为buttonStart\u单击WinForm中的buttonStop\u单击 以下是WinForm的代码： private void buttonStart_Click(object sender, EventArgs e) { //should start to listen to the TCP/IP

我有一个充当
套接字
侦听器（服务器端）的代码，我在
WinForms
和
Windows服务
中实现它。里面的一切都是一样的，只是我将
Windows服务
OnStart
和
OnStop
的实现改为
buttonStart\u单击
WinForm
中的
buttonStop\u单击

以下是
WinForm
的代码：


private void buttonStart_Click(object sender, EventArgs e) { //should start to listen to the TCP/IP         
    if (serverHandler.IsMyTargetPortBusy())
        return;
    try {
        serverHandler.InitiateMySocket(); //basically start the socket listening internally
        logInput("Start");
    } catch { //Fail to do the job. At this moment, don't do anything
        //TODO put something for logging
        return;
    }
}

private void buttonStop_Click(object sender, EventArgs e) {
    this.Close(); //Need to change to application exit for the service          
}



[2016-01-13 12:41:23.831 UTC] Attempting TCP/IP connection...
[2016-01-13 12:41:23.831 UTC] Attempting to connect to the TCP/IP server...
[2016-01-13 12:41:26.857 UTC] Connected to IP address: 127.0.0.1, Port: 5123
[2016-01-13 12:41:26.857 UTC] Connecting attempt through TCP/IP is successful!
[2016-01-13 12:41:26.889 UTC] Connection attempt: 1
[2016-01-13 12:41:26.889 UTC] Connection attempt is successful!


然后，我通过尝试使用通用TCP-IP客户端应用程序进行连接来测试代码。第一步是连接到
套接字
侦听器（服务器端）

建立连接时，客户端将输入一个具有以下代码的方法：


  clientHandler.InitiateSocket(myServerIpv4Address, serverPortNo);
  if (clientHandler.IsConnected()) {
      //Do something
  } else {
      //Do something, note the error message below
    logBox.WriteTimedLog("Connecting attempt through TCP/IP is failed! Timeout Occurs!\n", Color.Red);
  }


在
clientHandler.InitiateConnect中，我们有


//something else
clientSocket.LoopConnect(5, 3); //In the InitiateConnect


对于类型为
Socket
的
clientSocket
实例，我有以下方法：


//LoopConnect
public void LoopConnect(int noOfRetry, int attemptPeriodInSeconds) {
    int attempts = 0;
    while (!this.Connected && attempts < noOfRetry) {
        try {
            ++attempts;
            IAsyncResult result = this.BeginConnect(ipv4Address, portNo, endConnect, null);
            result.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(attemptPeriodInSeconds));
            Thread.Sleep(attemptPeriodInSeconds * 1000);
        } catch (Exception e) {
             //Something else
        }
        //Something else
    }
    //Something else
}

//endConnect
private void endConnect(IAsyncResult result) {
  try {
    this.EndConnect(result);
    if (this.Connected) {
      this.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(receiveCallback), this);
    } else if (ErrorMessageHandler != null) //ErrorMessageHandler is an event handler
      ErrorMessageHandler("End of connection attempt, fail to connect...\n");
  } catch (Exception e) {
      //Something
  }
}

//Receive callback
const int MAX_RECEIVE_ATTEMPT = 10;
int receiveAttempt = 0;
private void receiveCallback(IAsyncResult result) {
  System.Net.Sockets.Socket socket = null;
  try {
    socket = (System.Net.Sockets.Socket)result.AsyncState;  
    if (socket.Connected) {
      int received = socket.EndReceive(result);
      if (received > 0) {
        receiveAttempt = 0;
        byte[] data = new byte[received];
        Buffer.BlockCopy(buffer, 0, data, 0, data.Length); 
        //something else
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(receiveCallback), socket);
      } else if (receiveAttempt < MAX_RECEIVE_ATTEMPT) {
        ++receiveAttempt;
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(receiveCallback), socket);
      } else { //completely fails!
        if (ErrorMessageHandler != null) //Note the error message
          ErrorMessageHandler("receiveCallback is failed!\n"); 
        receiveAttempt = 0;
        this.Close();
      }
    }
  } catch (Exception e) { 
      //Something else
  }
}


令我惊讶的是，当连接到服务器时，我从
WinForms
得到的结果与从
Windows服务得到的结果不同

这是服务器处于
WinForm
时的我的客户端消息：


private void buttonStart_Click(object sender, EventArgs e) { //should start to listen to the TCP/IP         
    if (serverHandler.IsMyTargetPortBusy())
        return;
    try {
        serverHandler.InitiateMySocket(); //basically start the socket listening internally
        logInput("Start");
    } catch { //Fail to do the job. At this moment, don't do anything
        //TODO put something for logging
        return;
    }
}

private void buttonStop_Click(object sender, EventArgs e) {
    this.Close(); //Need to change to application exit for the service          
}



[2016-01-13 12:41:23.831 UTC] Attempting TCP/IP connection...
[2016-01-13 12:41:23.831 UTC] Attempting to connect to the TCP/IP server...
[2016-01-13 12:41:26.857 UTC] Connected to IP address: 127.0.0.1, Port: 5123
[2016-01-13 12:41:26.857 UTC] Connecting attempt through TCP/IP is successful!
[2016-01-13 12:41:26.889 UTC] Connection attempt: 1
[2016-01-13 12:41:26.889 UTC] Connection attempt is successful!


这是服务器处于Windows服务中时的“我的客户端”消息：


[2016-01-13 12:42:14.464 UTC] Attempting TCP/IP connection...
[2016-01-13 12:42:14.480 UTC] Attempting to connect to the TCP/IP server...
[2016-01-13 12:42:17.558 UTC] Connecting attempt through TCP/IP is failed! Timeout Occurs!
[2016-01-13 12:42:17.558 UTC] receiveCallback is failed!
[2016-01-13 12:42:20.245 UTC] Attempting TCP/IP connection...
[2016-01-13 12:42:20.245 UTC] Attempting to connect to the TCP/IP server...
[2016-01-13 12:42:23.261 UTC] Connected to IP address: 127.0.0.1, Port: 5123
[2016-01-13 12:42:23.261 UTC] Connecting attempt through TCP/IP is successful!
[2016-01-13 12:42:23.277 UTC] Connection attempt: 1
[2016-01-13 12:42:23.277 UTC] Connection attempt is successful!


问题

在
WinForms
应用程序中，连接在第一次尝试时工作。但是在
Windows服务中
我第一次尝试总是失败，必须重复第二次才能连接，尽管在内部，第一次失败意味着我已经重复了10次连接尝试（查看
receiveCallback
code）

现在，由于客户端生成的错误消息


[2016-01-13 12:42:17.558 UTC] Connecting attempt through TCP/IP is failed! Timeout Occurs!
[2016-01-13 12:42:17.558 UTC] receiveCallback is failed!


我设法缩小了导致错误的代码部分：

第一个来自这里


  clientHandler.InitiateSocket(myServerIpv4Address, serverPortNo);
  if (clientHandler.IsConnected()) {
      //Do something
  } else {
      //Do something, note the error message below
    logBox.WriteTimedLog("Connecting attempt through TCP/IP is failed! Timeout Occurs!\n", Color.Red);
  }


还有这里的第二个：


//Receive callback
const int MAX_RECEIVE_ATTEMPT = 10;
int receiveAttempt = 0;
private void receiveCallback(IAsyncResult result) {
  System.Net.Sockets.Socket socket = null;
  try {
    socket = (System.Net.Sockets.Socket)result.AsyncState;  
    if (socket.Connected) {
      int received = socket.EndReceive(result);
      if (received > 0) {
        receiveAttempt = 0;
        byte[] data = new byte[received];
        Buffer.BlockCopy(buffer, 0, data, 0, data.Length); 
        //something else
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(receiveCallback), socket);
      } else if (receiveAttempt < MAX_RECEIVE_ATTEMPT) {
        ++receiveAttempt;
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(receiveCallback), socket);
      } else { //completely fails!
        if (ErrorMessageHandler != null) //Note the error message
          ErrorMessageHandler("receiveCallback is failed!\n"); 
        receiveAttempt = 0;
        this.Close();
      }
    }
  } catch (Exception e) { 
      //Something else
  }
}



//接收回调
const int MAX_RECEIVE_trunt=10；
int receivetrust=0；
私有void receiveCallback（IAsyncResult结果）{
System.Net.Sockets.Socket Socket=null；
试一试{
套接字=（System.Net.Sockets.socket）result.AsyncState；
if（插座连接）{
int received=socket.EndReceive（结果）；
如果（收到>0）{
receivetrust=0；
字节[]数据=新字节[已接收]；
块复制（Buffer，0，data，0，data.Length）；
//别的
socket.BeginReceive（buffer，0，buffer.Length，SocketFlags.None，新异步回调（receiveCallback），socket）；
}否则如果（接收尝试<最大接收尝试）{
++接受尝试；
socket.BeginReceive（buffer，0，buffer.Length，SocketFlags.None，新异步回调（receiveCallback），socket）；
}否则{//完全失败！
if（ErrorMessageHandler！=null）//注意错误消息
ErrorMessageHandler（“receiveCallback失败！\n”）；
receivetrust=0；
这个。关闭（）；
}
}
}捕获（例外e）{
//别的
}
}


可悲的是，虽然我可以缩小错误的来源，但我无法解释原因，因此也不知道如何解决它。有人知道为什么吗

其他信息：


    

  • 起初，我认为这可能是因为服务启动的时间不够长。但即使我已经等了几分钟，结果也是一样的。这证明我错了
    •