我正在尝试获取从 QNetworkReply 下载的百分比,因为正在使用以下方式下载文件:
connect(reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(getDownloadData(qint64, qint64)) );
但是当我测试我的程序时,我总是得到:
进度:100
它输出两次,我从来没有得到低于 100 的任何东西。我希望每次下载进度发生变化时都会发出信号。
我怎样才能做到这一点?还是我在代码中犯了一个错误,阻止了它的发生?
编辑:@dubsjw 指出我使用 int 时出现舍入错误。现在,随着时间的推移,对于大图像,我从 0 增加到 100,但对于小图像,我仍然只得到 progress: 0 和 progress: 100 之间没有任何内容。我想发出一个由进度条接收的信号,该信号从 0 平滑增加到 100。我该怎么做?
文件下载器.h:
#ifndef FILEDOWNLOADER_H
#define FILEDOWNLOADER_H
#include <QObject>
#include <QByteArray>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>
class FileDownloader : public QObject
{
Q_OBJECT
public:
explicit FileDownloader(QUrl imageUrl, QObject *parent = 0);
virtual ~FileDownloader();
QByteArray downloadedData() const;
signals:
void downloaded();
private slots:
void fileDownloaded();
void getDownloadData(qint64 read, qint64 total);
private:
QNetworkAccessManager m_WebCtrl;
QByteArray m_DownloadedData;
QNetworkReply* reply;
};
#endif // FILEDOWNLOADER_H
文件下载器.cpp:
#include "filedownloader.h"
FileDownloader::FileDownloader(QUrl imageUrl, QObject *parent) :
QObject(parent)
{
QNetworkRequest request(imageUrl);
reply = m_WebCtrl.get(request);
connect(reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(getDownloadData(qint64, qint64)) );
connect(reply, SIGNAL(finished()),this, SLOT(fileDownloaded()));
}
FileDownloader::~FileDownloader()
{
}
void FileDownloader::fileDownloaded()
{
m_DownloadedData = reply->readAll();
//emit a signal
reply->deleteLater();
emit downloaded();
}
QByteArray FileDownloader::downloadedData() const
{
return m_DownloadedData;
}
void FileDownloader::getDownloadData(qint64 read, qint64 total)
{
qDebug() << "Progress:";
qint64 percent = (read / total) * 100;
qDebug() << percent;
}