Question

我正在尝试使用QNetworkAcessManager来获取网址的来源。但似乎信号槽复合体存在问题！

我的onFinished(QNetworkReply*)永远不会被触发！为什么呢？

void Worker::start(QString url)
{
    QNetworkAccessManager manager;
    QNetworkReply *reply = manager.get(QNetworkRequest(QUrl(url)));
    QObject::connect(reply, SIGNAL(finished(QNetworkReply*)), this, SLOT(onFinished(QNetworkReply*)));
}

void Worker::onFinished(QNetWorkReply * reply)
{
    qDebug() << "Slot has been triggered!";

    QString html = reply->readAll();
}

修改

正如“Oleg Shparber”所述，这是我的新代码（也不起作用）：

void Worker::start(QString url)
{
    QNetworkAccessManager *manager = new QNetworkAccessManager();
    QNetworkReply *reply = manager->get(QNetworkRequest(QUrl(url)));
    QObject::connect(reply, SIGNAL(finished()), this, SLOT(onFinished()));


void Worker::onFinished()
{
    qDebug() << "Slot has been triggered!";

    QString html = reply->readAll();
}

Answer 1

在控件到达start()方法结束后，您的QNetworkAccessManager会立即被破坏（有关详情，请参阅RAII）。您需要动态创建QNetworkAccessManager并在请求执行时保持活动状态。

此外，您正在连接不存在的信号。有QNetworkReply::finished()，但没有QNetworkReply::finished(QNetworkReply*)。如果您需要指向QNetworkAccessManager::finished(QNetworkReply*)的指针，也可以使用QNetworkReply。

QNetworkAccessManager - 完成的信号永远不会触发插槽

1 个答案: