Question

我使用的QTcpServer应该单独侦听端口。语言是带有Qt 5.9的c ++。该应用程序必须使用MingW在Win和Linux下运行。 QTcpServer的listen方法将标准参数用于套接字选项。对于Win10，Linux将这些选项默认设置为监听端口的单次使用，因此监听工作正常。不幸的是，Win7提供了共享用法，我必须避免这种用法。我发现QAbstractSocket类让我使用BindFlag :: DontShareAddress创建了一个套接字。我可以将socketdescriptor转发到QTcpServer。然后方法侦听失败（不侦听），方法是声明：在侦听时调用了QTcpServer :: listen（）。我使用netstat检查端口状态。我的代码示例如下：

    bool TcpServer::init(QString ipAddress, quint16 port, Command::RoutingProperty clientSocketKind, QString interfaceName)
{
    if (mServerIsInit == true) // only 1 server instance
    {
        return false;   

    mServer = new (std::nothrow) QTcpServer();
    if (mServer == nullptr)
    {
        return false;
    }

    mClientSocketKind = clientSocketKind;
    mInterfaceName = interfaceName;

// tries to set socket properties to a non sharing port
    QTcpSocket tsocket;

   if (!tsocket.bind(QHostAddress(ipAddress), port, QAbstractSocket::BindFlag::DontShareAddress))
    {
        qDebug() << "Socket bind fails";
    }
    else
    {
        qDebug() << "Socket bind success";
    }
    sd = tsocket.socketDescriptor(); // valid socket descriptor

    if (!mServer->setSocketDescriptor(sd))
    {
        qDebug() << "SocketDescriptor fails";
    }

    sd = mServer->socketDescriptor();
    qDebug() << "Socketdescriptor Server " << sd;
//end tries to set socket properties to a non sharing port

    if (mServer->listen(QHostAddress(ipAddress), port)) // fails with message ... is always listening
//  if (mServer->mServer->isListening()) // is not listening tells netstat
    {
        qDebug() << "Server status for listening ok: " << mServer->isListening();
        qDebug() << "Server listen on " << mServer->serverAddress() << ":" << mServer->serverPort();

        connect(mServer, SIGNAL(newConnection()), this, SLOT(newConnection()));
        connect(mServer, SIGNAL(acceptError(QAbstractSocket::SocketError)), this, SLOT(socketErr(QAbstractSocket::SocketError)));

        mServerIsInit = true;
        return true;
    }
    else
    {
        qDebug() << "Server status for listening fail" << mServer->isListening();
        delete mServer;
        mServer = nullptr;
        return false;
    }
}

感谢任何想法如何设置套接字选项以专用于侦听端口。

马丁

Answer 1

根据评论，您可能需要在调用listen之前在套接字描述符上显式调用QTcpServer::setSocketDescriptor。

以下代码未经测试，但应该可以使您有所了解...

if (!tsocket.bind(QHostAddress(ipAddress), port, QAbstractSocket::BindFlag::DontShareAddress)) { qDebug() << "Socket bind fails"; } else { qDebug() << "Socket bind success"; } sd = tsocket.socketDescriptor(); // valid socket descriptor /* * Now make an explicit call to `listen' so that the socket descriptor * can be passed to QTcpSocket::setSocketDescriptoy. */ if (listen(sd, SOMAXCONN) == SOCKET_ERROR) { printf("Listen failed with error: %ld\n", WSAGetLastError()); closesocket(sd); WSACleanup(); /* * Handle error. */ } if (!mServer->setSocketDescriptor(sd)) { qDebug() << "SocketDescriptor fails"; }

顺便说一句，请注意，您需要更加谨慎地处理错误-只需致电qDebug，然后继续操作就会在某个时候再次咬住您。

如何设置QTcpServer使用Win7在端口上单独侦听

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