c++ - 重构为独立类后，QNetworkRequest (HTTP GET) 不会触发

Question

我最近开始了对大约 2 个月前编写的大型单片音频播放器应用程序进行模块化的繁琐过程。

这个过程进行得相当顺利，尽管其中一种方法(ScrobbleMedia - 可以预见的是它会发出 HTTP 请求以将有关播放轨道的信息提交到 last.fm)似乎不再发出网络请求。

但是，正在正确构建将传递给 QNetworkAccessManager 实例/QNetworkRequest 的 QUrl 对象。

为了比较，代码的功能性 Mercurial 修订版可在 BitBucket 上获得。 .

ScrobbleMedia 方法在重构后目前看起来像这样:

#include "scrobblemedia.h"

#include <QDebug>
#include <cstdio>

ScrobbleMedia::ScrobbleMedia(QString asUsername, QString asPassword,
                         QString asArtist, QString asTrack, QString asAlbum)
{

    QString KEndPointURL = "http://lastfmstats.livefrombmore.com/universalscrobbler/scrobble.php";
    QUrl iScrobbleEndPoint(KEndPointURL);

      QNetworkAccessManager *iScrobbleDispatcher = new QNetworkAccessManager(this);


iScrobbleEndPoint.addQueryItem("submissionType","track");
iScrobbleEndPoint.addQueryItem("username", asUsername);
iScrobbleEndPoint.addQueryItem("password", asPassword);
iScrobbleEndPoint.addQueryItem("artist", asArtist);
iScrobbleEndPoint.addQueryItem("track", asTrack);
iScrobbleEndPoint.addQueryItem("album", asAlbum);
iScrobbleEndPoint.addQueryItem("number","1");
iScrobbleEndPoint.addQueryItem("duration","200");

iScrobbleDispatcher->get(QNetworkRequest(iScrobbleEndPoint));
connect(iScrobbleDispatcher, SIGNAL(finished(QNetworkReply*)),
 SLOT(replyFinished(QNetworkReply*)));

// QString Outside = iScrobbleEndPoint.toEncoded();

qDebug()  << "Received: " + 
  asUsername + " " + 
   asPassword + " " + 
    asArtist + " " +
     asTrack + " " + 
      asAlbum;

qDebug() << iScrobbleEndPoint.toString();

}

ScrobbleMedia::~ScrobbleMedia() {

}

关联的头文件如下所示:

#ifndef SCROBBLEMEDIA_H
#define SCROBBLEMEDIA_H

#include <QString>
#include <QtNetwork>
#include <QUrl>
#include <QNetworkAccessManager>



class ScrobbleMedia : public QObject
{
     Q_OBJECT;


private:

public:

    ScrobbleMedia(QString asUsername, QString asPassword, QString asArtist, QString asTrack, QString asAlbum);
    ~ScrobbleMedia();

};

#endif // SCROBBLEMEDIA_H

我目前正在 Windows 7 x86-64 下针对 Qt 库的 4.7.0 版 MinGW 构建(作为 Qt SDK 2010.05 的一部分包含在内)构建应用程序本身。

如有任何帮助，我们将不胜感激。

提前致谢。

Answer 1

在阅读了许多不同的信息来源(其中大部分是相互矛盾的)之后，我发现以下结果是一个有效的解决方案——尽管调试输出中有一个似乎不影响操作的外观问题(Object::connect: No such signal QNetworkReplyImpl::finished(QNetworkReply*) in ../AudioPlayer/scrobblemedia.cpp:29):

在 scrobblemedia.cpp 中:

#include "scrobblemedia.h"

#include <QDebug>
#include <cstdio>

ScrobbleMedia::ScrobbleMedia(QString asUsername, QString asPassword,
                             QString asArtist, QString asTrack, QString asAlbum)
{

    QByteArray iDataSink;
    QEventLoop iLoop;

    QString KEndPointURL = "http://lastfmstats.livefrombmore.com/universalscrobbler/scrobble.php";
    QUrl iScrobbleEndPoint(KEndPointURL);

    iScrobbleEndPoint.addQueryItem("submissionType","track");
    iScrobbleEndPoint.addQueryItem("username", asUsername);
    iScrobbleEndPoint.addQueryItem("password", asPassword);
    iScrobbleEndPoint.addQueryItem("artist", asArtist);
    iScrobbleEndPoint.addQueryItem("track", asTrack);
    iScrobbleEndPoint.addQueryItem("album", asAlbum);
    iScrobbleEndPoint.addQueryItem("number","1");
    iScrobbleEndPoint.addQueryItem("duration","200");

    QNetworkAccessManager iScrobbleDispatcher;
    QNetworkRequest iScrobbleRequest(iScrobbleEndPoint);
    QNetworkReply *iScrobbleReply = iScrobbleDispatcher.get(iScrobbleRequest);

    QObject::connect(iScrobbleReply, SIGNAL(finished(QNetworkReply*)), &iLoop,
     SLOT(quit()));

    iDataSink = iScrobbleReply->readAll();

    qDebug()  << "Received: " + asUsername + " " + asPassword + " " + asArtist + " " + asTrack + " " + asAlbum;

    qDebug() << iScrobbleEndPoint.toString();

    iLoop.exec();
}

ScrobbleMedia::~ScrobbleMedia() {

}

void ScrobbleMedia::replyFinished(QNetworkReply*) {

}

void ScrobbleMedia::reallyDone() {

    qDebug() << "We've probably successfully Scrobbled...";
}

在 scrobblemedia.h 中:

#ifndef SCROBBLEMEDIA_H
#define SCROBBLEMEDIA_H

#include <QString>
#include <QtNetwork>
#include <QUrl>
#include <QNetworkAccessManager>



class ScrobbleMedia : public QObject
{
     Q_OBJECT


private:


public:

    ScrobbleMedia(QString asUsername, QString asPassword, QString asArtist, QString asTrack, QString asAlbum);
    ~ScrobbleMedia();

private slots:
    void replyFinished(QNetworkReply*);
    void reallyDone();

};

#endif // SCROBBLEMEDIA_H

感谢大家的帮助。

希望这段代码将来能成为其他人的有用模板。