Question

我正按照an example in the QtWebkit documentation编写缩略图生成器。我想避免错误页面的屏幕截图，例如404 not found或503 Internal server error。

但是，即使页面发出HTTP错误，QWebPage::loadFinished()信号始终会以ok = true发出。 QtWebkit中有没有办法检查响应的HTTP状态代码？

Answer 1

事实证明，您需要监控与QWebPage关联的QNetworkAccessManager并等待finished(...)信号。然后，您可以通过询问QNetworkRequest::HttpStatusCodeAttribute属性来检查HTTP响应并检查其状态代码。

在代码中更好地解释：

void MyClass::initWebPage()
{
  myQWebPage = new QWebPage(this);
  connect(
    myQWebPage->networkAccessManager(), SIGNAL(finished(QNetworkReply *)),
    this, SLOT(httpResponseFinished(QNetworkReply *))
  );
}

void MyClass::httpResponseFinished(QNetworkReply * reply)
{
  switch (reply->error())
  {
    case QNetworkReply::NoError:
      // No error
      return;
    case QNetworkReply::ContentNotFoundError:
      // 404 Not found
      failedUrl = reply->request.url();
      httpStatus = reply->attribute(
        QNetworkRequest::HttpStatusCodeAttribute).toInt();
      httpStatusMessage = reply->attribute(
        QNetworkRequest::HttpReasonPhraseAttribute).toByteArray();
      break;
    }
}

还有更多NetworkErrors可供选择，例如对于TCP错误或HTTP 401。

Answer 2

这就是我在移植项目中使用的内容。它会检查回复并决定是否开始提出请求。退出部分正在进行中，但我留下了评论。

QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
Q_CHECK_PTR(reply);

QVariant statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
if (!statusCode.isNull() && statusCode.toInt() >= 400){
    //INVALID_SERVER_RESPONSE_BACKOFF;
    qDebug() << "server returned invalid response." << reply->attribute(QNetworkRequest::HttpReasonPhraseAttribute).toString();
    return;
}else if (!statusCode.isNull() && statusCode.toInt() != 200){
    //INVALID_SERVER_RESPONSE_NOBACKOFF;
    qDebug() << "server returned invalid response." << reply->attribute(QNetworkRequest::HttpReasonPhraseAttribute).toString();
    return;
}

QtWebkit：如何检查HTTP状态代码？

2 个答案: