如何同步QNetworkAccessManager？

Question

我的deleteIdList变量来自replyFinished(QNetworkReply*)函数。但deleteIdList变量返回为空。但是，它必须返回任何内容..我想同步QNetworkAccessManager..

    QNetworkAccessManager *manager = new QNetworkAccessManager(this);
    connect(manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(replyFinished(QNetworkReply*)));

    foreach (QString delIdList, deleteIdList) {

    serviceUrl = "http://localhost:8080/limit_id="+delIdList+"&false";
    requestUrl = QString("%1%2:%3%4").arg(scheme).arg(qstr).arg(QString::number(svcPort)).arg(serviceUrl);

    QUrl url(requestUrl);
    QNetworkRequest request;
    request.setUrl(url);
    manager->get(request);

  }

如何同步QNetworkAccessManager？

Answer 1

我可能会迟到，但我认为这可以帮助其他面临这个问题的人。

QNetworkAccessManager *networkMgr = new QNetworkAccessManager(this);
QNetworkReply *reply = networkMgr->get( QNetworkRequest( QUrl( "http://www.google.com" ) ) );

QEventLoop loop;
QObject::connect(reply, SIGNAL(readyRead()), &loop, SLOT(quit()));

// Execute the event loop here, now we will wait here until readyRead() signal is emitted
// which in turn will trigger event loop quit.
loop.exec();

// Lets print the HTTP GET response.
qDebug( reply->readAll());

Source : developer.nokia.com

Answer 2

呃..。你干吗呢？您创建了一个QNetWorkManager，将完成的信号连接到replyFinished插槽，并期望在发送请求之前就得到来自replyFinished的结果？对不起，但从我在你的代码中看到的，我会说它是无法修复的。

foreach (QString delIdList, deleteIdList)必须在replyFinished插槽中，当deleteIdList以某种方式作为请求的结果时。和

    QUrl url(requestUrl);
    QNetworkRequest request;
    request.setUrl(url);
    manager->get(request);

必须在连接下面的循环之外。但当然，你的代码是如此的错误，我的“提示”只是粗略地猜测你可能打算做什么。

Answer 3

这个问题有点难理解--但我有一些建议，那就是:永远不要使用QNetworkAccessManager的finished信号。而是连接到QNetworkReply的已完成插槽。

QNetworkAccessManager *manager = new QNetworkAccessManager(this);

foreach (QString delIdList, deleteIdList) {

    serviceUrl = "http://localhost:8080/limit_id="+delIdList+"&false";
    requestUrl = QString("%1%2:%3%4").arg(scheme).arg(qstr).arg(QString::number(svcPort)).arg(serviceUrl);

    QUrl url(requestUrl);
    QNetworkRequest request;
    request.setUrl(url);
    QNetworkReply *reply = manager->get(request);
    connect(reply,SIGNAL(finished()),this,SLOT(replyFinished()));
}

然后，在replyFinished插槽中，您可以调用sender()来接收指向回复的指针。通过这种方式，您可以“同步”并找出哪个回复属于哪个请求。