C# - TcpClient - 无法建立连接，因为目标机器主动拒绝它

Question

您好，我目前每分钟都在使用 Zebra 打印机创建一个新连接，它可以正常工作 5 到 8 个小时。之后我得到了 "No connection could be made because the target machine actively refused it" 错误。一旦出现此错误，就无法重新连接打印机，直到我完全关闭并启动 Zebra 打印机。

我没有正确关闭我的 tcpClient steam，或者在大约 300 次重新连接后无法导致错误出现的原因

我的代码：

//CLASS MEMBERS
private TcpClient client = new TcpClient(); 
private Timer TimZebraTimeOut;
private int ZebraTimeOutTime = 60000;
private bool NewConnectionNeeded = true;

//NORMALY CALLED IN CONSTRUCTOR
TimZebraTimeOut = new Timer(TimZebraTimeOutCallback, null,this.ZebraTimeOutTime, Timeout.Infinite);

//CLASS METHODS
private void CreateNewConnectionIfComTimeOut
{
    try
    {
        if (this.NewConnectionNeeded ) // If time is out Create new connection with Zebra Printer
        {
            //Close last connexion open
            client.Client.Close();
            //Create a new one
            client = new TcpClient();
            // Add Read/Write TimeOut
            client.SendTimeout = 10000;
            client.ReceiveTimeout = 10000;                    
            //Create TCP Connection
            client.Connect(this.config.IpAddress, this.config.Port);
            // Connection with PrinterEstablished
            this.NewConnectionNeeded = false; 
            this.iLog.Info("CommunicationWithZebraPrinter : New connection With Labeler Established "); // If New connection not caused by timeout

        }
    }
    catch (Exception exception)
    {
        // Write exception in Log 
        this.iLog.Error("CommunicationWithZebraPrinter : Can't establish a connection with printer: " + exception.Message.ToString());
    }
}

// Zebra Communication Timer interrupt callback function
private void TimZebraTimeOutCallback(Object state)
{
    // Flag That ZebraCom have timeout
    this.NewConnectionNeeded= true;
    //Restart Zebra Com TimeOut 
    TimZebraTimeOut.Change(this.ZebraTimeOutTime, Timeout.Infinite);
}

非常感谢

丹尼尔

Netstat 视图：

建立新连接时，3 个本地端口递增。

Answer 1

我的问题是 Zebra 打印机默认有 300 秒的连接超时，我每分钟都在创建一个新连接。在短暂的持续时间（6 小时）后，我的打印机连接缓冲区溢出。我只是将打印机超时更改为 1 分钟并轮询打印机以检测断开连接。

C# - TcpClient - 无法建立连接，因为目标机器主动拒绝它

C# - TcpClient - No connection could be made because the target machine actively refused it

c#

tcpclient

zebra-printers