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我有一个 QT 程序，它使用 QNetworkAccessManager 通过 Http POST 上传一组文件。一切都可以正常上传，但我无法将 uploadProgress 与进度条连接起来。
这是上传的代码:
QNetworkAccessManager *networkManager = new QNetworkAccessManager(this);
while (numNetConn > 3) {
qDebug("Waiting for the number of transfers to decrease. [%d]", numNetConn);
QTest::qWait(500);
}
QNetworkReply* reply = networkManager->post(request, multiPart);
multiPart->setParent(reply); // delete the multiPart with the reply
connect(reply, SIGNAL(finished()), this, SLOT(onGetReply()));
connect(reply, SIGNAL(uploadProgress(qint64, qint64)), SLOT(progressChanged(qint64, qint64)));
void MainWindow::progressChanged(qint64 a, qint64 b) {
if (b > 0) {
qDebug() << "Uploading " << a << "/" << b << "%" << (double)a/(double)b*100.0;
ui->progUpload->setValue((a/b)*100);
qApp->processEvents();
}
}
调试窗口在上传时愉快地显示了很多进度，但 UI 直到上传结束时跳到 100% 时才更新。
...
Uploading 171606016 / 172918683 % 99.2409
Uploading 171835392 / 172918683 % 99.3735
Uploading 172064768 / 172918683 % 99.5062
Uploading 172294144 / 172918683 % 99.6388
Uploading 172523520 / 172918683 % 99.7715
Uploading 172769280 / 172918683 % 99.9136
Uploading 172918683 / 172918683 % 100
我在更新 UI 的 progressChanged() 函数中缺少什么？