当在错误槽中启动事件循环时发生ContentNotFoundError时,QNetworkReply会发出两次错误信号

QNetworkAccessManager *manager = new QNetworkAccessManager(this);
QNetworkReply *reply = manager->get(QNetworkRequest(QUrl("http://www.example.com")));

connect(reply, &QNetworkReply::errorOccurred, [=](QNetworkReply::NetworkError error) {
    if (error == QNetworkReply::ContentNotFoundError) {
        // 处理ContentNotFoundError错误
    } else {
        // 处理其他错误
    }
});