QNetworkAccessManager 不发出完成信号

Question

我正在尝试使用 QNetworkAccessManager 进行多个请求，即使我连接插槽 QNetworkAccessManager 也无法发出 finished() 信号。

这是我实现的代码。

void GetNetwork::getAction(QStringList *urls, QList<QByteArray> *result)
{
    uint size=urls->size();

    multiGetResult=result;
    getUrls=urls;
    setFlags();

    for(uint x=0;x<size;x++)
    {
        int test=caluculateIndex(x);
       getNAM[test]->get(QNetworkRequest(QUrl(urls->at(x))));
    }


    //qDebug()<<reply->readAll();

    while (!waitWithFlag())  QThread::msleep(15);

    delete threadFlag;
}

bool GetNetwork::setMultipleGet(uint number)
{
    int diff=number-(getNAM.size()-1);

    if(((getNAM.size()-1)+diff)<0)
        return false;

    for(int i=0;i<diff;i++)
    {
        getNAM.append(new QNetworkAccessManager(this));
        connect(getNAM[getNAM.size()-1],SIGNAL(finished(QNetworkReply*)),this,SLOT(handleMultiRequest(QNetworkReply*)));
    }

    for(int i=diff;i<0;i++)
    {
        disconnect(getNAM[getNAM.size()-1],SIGNAL(finished(QNetworkReply*)),this,SLOT(handleMultiRequest(QNetworkReply*)));
        delete getNAM[getNAM.size()-1];
        getNAM.remove(getNAM.size()-1);
    }
    return true;
}

void GetNetwork::handleMultiRequest(QNetworkReply * reply)
{
    int index=getUrls->indexOf(reply->url().toString());

    if(reply->error()!=QNetworkReply::NoError||index==-1)
    {
        QString error=QString("Network Error file:%1 line:%2 error:%3")
                             .arg(__FILE__)
                             .arg(__LINE__)
                             .arg(reply->errorString());

        emit errorOccured(error);
        return;
    }

    multiGetResult->insert(index,reply->readAll());
    threadFlag[index]=true;
}

这些代码有什么问题？我想不通。

谢谢。

Answer 1

首先，QNetworkAccessManager 不需要单独的线程，因为它在 Qt 4.8.1 之后在内部运行在单独的线程（异步）中。

其次，您仅将 QNetworkAccessManager 的最后一个实例与已完成的插槽连接，而不是这样做，而是将 QNetworkAccessManager 的每个实例与 handleMultiRequest Slot 连接，并在调用插槽时不断增加计数。你不需要睡眠之类的东西，这都是事件驱动的。 所以，

void GetNetwork::handleMultiRequest(QNetworkReply * reply)
{
    int index=getUrls->indexOf(reply->url().toString());

    if(reply->error()!=QNetworkReply::NoError||index==-1)
    {
        QString error=QString("Network Error file:%1 line:%2 error:%3")
                             .arg(__FILE__)
                             .arg(__LINE__)
                             .arg(reply->errorString());

        emit errorOccured(error);
        return;
    }

    count++;
   if(count == num_get_requests)
   {
       emit
         allDone()
   }
}

Answer 2

我改变了像 Adnan 想法这样的功能

void GetNetwork::handleMultiRequest(QNetworkReply * reply)
{
    int index=getUrls->indexOf(reply->url().toString());

    if(reply->error()!=QNetworkReply::NoError||index==-1)
    {
        QString error=QString("Network Error file:%1 line:%2 error:%3")
                             .arg(__FILE__)
                             .arg(__LINE__)
                             .arg(reply->errorString());

        emit errorOccured(error);
        return;
    }

    multiGetResult->insert(index,reply->readAll());
    threadDoneCounter++;
    if(threadDoneCounter==getUrls->size())
        emit threadsAreDone();
}

和

void GetNetwork::getAction(QStringList *urls, QList<QByteArray> *result)
{
    uint size=urls->size();

    multiGetResult=result;
    getUrls=urls;
    threadDoneCounter=0;

    for(uint x=0;x<size;x++)
    {
        int test=caluculateIndex(x);
       getNAM[test]->get(QNetworkRequest(QUrl(urls->at(x))));
    }



    QEventLoop eLoop;
    connect(this,SIGNAL(threadsAreDone()),&eLoop,SLOT(quit()));
    eLoop.exec();

    disconnect(this,SIGNAL(threadsAreDone()),&eLoop,SLOT(quit()));
}