HTTP请求中的Qnetworkreply和QnetworkAccessManager超时

Question

当我执行HTTP请求时如何设置超时？

我有此代码：

{
    QNetworkRequest request;
    request.setUrl(QUrl("http://www.foo.com"));
    request.setRawHeader("User-Agent", USER_AGENT.toUtf8());
    request.setRawHeader("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
    request.setRawHeader("Accept",
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    request.setRawHeader("Accept-Language", "en-us,en;q=0.5");
    request.setRawHeader("Connection", "Keep-Alive");
    reply = m_networkManager->get(request);
    QEventLoop loop;
    connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
    loop.exec();
}

在何处以及如何设置请求的某种超时？

Answer 1

QTimer timer;    
timer.setSingleShot(true);
QEventLoop loop;
connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
timer.start(30000);   // 30 secs. timeout
loop.exec();
if(timer.isActive()) {
    timer.stop();
    if(m_reply->error() > 0) {
      ... // handle error
    }
    else {      
      int v = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
      if (v >= 200 && v < 300) {  // Success
        ...
      }
    }
} else {
   // timeout
   disconnect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
   reply->abort();
}

Answer 2

检查一下：

https://doc.qt.io/qt-5/qnetworkrequest.html#settransfertimeout

void qnetworkrequest :: setTransfertimeout（int timeout =DefaultTransferTimeOutConstant）将超时设置为转移超时以毫秒。

如果未在超时之前传输字节，则将中止转移到期。零表示未设置计时器。如果没有提供任何论点，超时是qnetworkRequest :: DefaultTransferTimeOutConstant。如果这函数未调用，超时是禁用的，并且具有值零。

此功能是在QT 5.15中引入的。