获取所有活动网卡

    int ipInc = 0;

    QStringList ipList;
    ipList.clear();

    QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();
    QList<QNetworkInterface> ipDevList = QNetworkInterface::allInterfaces();

#ifdef Q_OS_ANDROID
    ipList << "Android Boardcast";
#endif

    for (int i = 0; i < ipDevList.size(); ++i) {
        bool ipReady = false;
        QList<QNetworkAddressEntry> tmpIPlist = ipDevList.at(i).addressEntries();


        // 排除所有未连接的网卡
        QNetworkInterface tmpNet = ipDevList.at(i);
        QNetworkInterface::InterfaceFlags interFlags;
        interFlags = tmpNet.flags();
        if(!((interFlags&QNetworkInterface::IsUp) &&
            (interFlags&QNetworkInterface::IsRunning) &&
            (interFlags&QNetworkInterface::CanBroadcast) &&
            (interFlags&QNetworkInterface::CanMulticast) &&
            !(interFlags&QNetworkInterface::IsLoopBack)))
        {continue;}

        QString tmpIp;
        for (int y=0; y<tmpIPlist.size(); ++y)
        {QNetworkAddressEntry xx = tmpIPlist.at(y);

            if (xx.ip() != QHostAddress::LocalHost && xx.ip().toIPv4Address() )
            {
                ipReady = true;
                tmpIp = xx.ip().toString();
                break;
            }
        }
        if(true == ipReady)
        {ipList << tmpIp + "(" + ipDevList.at(i).humanReadableName() + ")";
            if(tmpIp == lastUdpIp)
            {autoLinkIpSeqInList = ipInc;}
            ipInc++;
        }
    }
    qDebug() << "ipList:" << ipList;

在 TCP SERVER 中获取 CLIENT 的 IP 及端口

//clientIP = tcpSocket->peerAddress().toString();  // 网上的这种方法不可用, 会多出来一些字符
quint32 ipv4 = tcpSocket->peerAddress().toIPv4Address();
char xx[30];
sprintf(xx, "%d.%d.%d.%d",ipv4>>24,(ipv4>>16)&0xFF,(ipv4>>8)&0xFF ,ipv4&0xFF);
clientIP = xx;
clientPort = tcpSocket->peerPort();