QNetworkAccessManager 不会启动

Question

对 Qt 有点陌生，正在尝试向网站发出 HTTP GET 请求。问题是它不发送任何东西。我已经检查了小提琴手。没有动静。没有错误，没有触发信号。

我还检查了我是否有任何其他可能使用的网络接口，所以我禁用了它们但没有帮助

这是来源：

linkslooker::linkslooker(QThread *thread){
    this->mainThread = thread;
    Loop();
}

void linkslooker::Loop(){
  //  while(true){
        qDebug() << "Looking for sites. Accessability:" << qnam.networkAccessible(); // Always 1

        mainThread->msleep(1000); //To slow down the loop

        QNetworkRequest req(QUrl("http://www.test.com"));
        reply = qnam.get(req); //Get request to a QNetworkReply

        if(reply->error() != QNetworkReply::NoError)
          qDebug("network error!"); //There are no errors

        connect(reply, SIGNAL(finished()),
                SLOT(httpFinished())); //Finish request signal
        connect(reply, SIGNAL(readyRead()),
                this, SLOT(httpReadyRead())); //Read to start signal
        connect(reply, SIGNAL(downloadProgress(qint64,qint64)),
                this, SLOT(updateDataReadProgress(qint64,qint64))); //Reading Signal
        connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
                this, SLOT(slotError(QNetworkReply::NetworkError))); //Error Signal
  //  }
}


void linkslooker::httpFinished(){
    qDebug() <<  QString::fromUtf8(m_data);
}

void linkslooker::slotError(QNetworkReply::NetworkError e) {
    qDebug() << "slotError" << e ; //Not fired up
}
void linkslooker::httpReadyRead()
{
   m_data.append(reply->readAll());
   qDebug() << "READY TO READ";
}

void linkslooker::updateDataReadProgress(qint64 bytesRead, qint64 totalBytes)
{
    if (httpRequestAborted)
        qDebug() << "Network request Aborted";
        qDebug() << "Have read " << bytesRead << "Out of " << totalBytes;
}

这里是header供参考：

#ifndef LINKSLOOKER_H
#define LINKSLOOKER_H
#include <QCoreApplication>
#include <QQueue>
#include <QtNetwork>
#include <QList>
#include <QNetworkAccessManager>

class linkslooker:public QObject{

    Q_OBJECT
public:
    linkslooker(QThread *);
    ~linkslooker();

private:
    void Loop();
    QThread *mainThread;
    QQueue<QString> websites;
    QList<QString> searched;
    QNetworkAccessManager qnam;
    QNetworkReply *reply;
    bool httpRequestAborted;
    QByteArray m_data;
private slots:
      void httpFinished();
      void httpReadyRead();
      void updateDataReadProgress(qint64 bytesRead, qint64 totalBytes);
      void slotError(QNetworkReply::NetworkError);
};

#endif // LINKSLOOKER_H

Answer 1

发现问题：

在调用这个 class 时，我没有给它一个要保存的变量，所以在它附加了所有信号之后 - class 被销毁了（因为它超出了我认为的范围？)

必须从这里更改：

int main(int argc, char *argv[])
{
   QCoreApplication a(argc, argv);
   linkslooker(a.thread());
   return a.exec();
}

为此：

int main(int argc, char *argv[])
{
   QCoreApplication a(argc, argv);
   linkslooker ll(a.thread());
   return a.exec();
}

QNetworkAccessManager 不会启动

QNetworkAccessManager won't fire up

c++

qt

networking

qnetworkaccessmanager