void FileDownLoad::start()

{

m_file = new QFile(m_filePath, this);//m_filePath下载地址

if (!m_file->open(QIODevice::WriteOnly)) {

emit result(false, tr("Write file error!\n") + m_file->errorString());

return;

}

QUrl u(m_url);

QNetworkRequest request(u);

QNetworkReply *reply = m_accessManager.get(request);

m_reply = reply;

connect(reply, SIGNAL(finished()), this, SLOT(onReplyFinished()));//处理下载结果

connect(reply, SIGNAL(downloadProgress(qint64,qint64)), this, SLOT(updateDataReadProgress(qint64,qint64)));//更新下载进度

}

void FileDownLoad::onReplyFinished()

{

QNetworkReply *reply = dynamic_cast (sender());

if (!reply){

emit result(false, "reply is null!");

return;

}

if (reply->error() != QNetworkReply::NoError) {

QString errInfo = QString("errorID:%1, errorString:%2").arg(reply->error()).arg(reply->errorString());

emit result(false, errInfo);

return;

}

QByteArray data = reply->readAll();

if (!data.isEmpty()) {

int writeBytes = m_file->write(data);

m_file->flush();

if (writeBytes != data.size()) {

emit result(false, tr("Write file error\n") + m_file->errorString());

return;

}

}

// check filesize

int contentLength = reply->header(QNetworkRequest::ContentLengthHeader).toInt();

if (contentLength == 0 || m_file->size() == 0 || contentLength != m_file->size()) {

emit result(false, tr("Network error! code 400"));

return;

}

emit result(true, "");

}