node.js - 有错误代码时 QNetworkReply readAll 响应为空

Question

当 QNetworkReply::error() != NoError 时，QNetworkReply::readAll 的响应为空。这正常吗？

我有一个 Node+Express 服务器，当 http 状态不同于 200 时，它总是发送详细描述；我无法从 QNAM 上的 Qt 客户端获取此描述。 Qt版本为5.3，操作系统Win 7 64b。

这是我的代码，我真的认为这没有帮助。

PendingRequest *Foo::sendMsg(QStandardItem *requestItem, HTTP_METHOD_ID method, QString path)
{
    PendingRequest *pReq = new PendingRequest(method);

    QString url = QString("https://%1:%2%3").arg(host, QString::number(port), path);
    QNetworkRequest qNetReq = QNetworkRequest(QUrl(url));

    //set headears
    qNetReq.setHeader(QNetworkRequest::KnownHeaders::UserAgentHeader, HttpUserAgent);
    qNetReq.setRawHeader("Connection", "Keep-Alive");
    if(!credentials.isEmpty())
    {
        qNetReq.setRawHeader("Authorization", QByteArray("Basic ")+credentials);
    }
    if(!sessionId.isEmpty())
    {
        qNetReq.setRawHeader("Session-Id", sessionId);
    }

    //send request
    QNetworkReply *reply;
    if(method == HTTP_METHOD_ID::POST)
    {
        qNetReq.setHeader(QNetworkRequest::KnownHeaders::ContentTypeHeader, "application/json");
        QByteArray data = outHandlerList[outHandlerIndex](requestItem);
        reply = netManager.post(qNetReq, data);
    }
    else
    {
        reply = netManager.get(qNetReq);
    }

    connect(reply, SIGNAL(finished()), this, SLOT(handleResponse()));
    connect(reply, SIGNAL(sslErrors(QList<QSslError>)), this, SLOT(handleSslErrors(QList<QSslError>)));

    return pReq;
}

这是我处理响应的地方:

void Foo::handleResponse()
{
    QNetworkReply *reply = qobject_cast<QNetworkReply *>(sender());

    if(reply->hasRawHeader("Session-Id"))
        sessionId = reply->rawHeader("Session-Id");

    PendingRequest *pReq = pendingRequestMap.contains(reply) ? pendingRequestMap.take(reply) : 0;
    Q_ASSERT(pReq);

    QStandardItem *responseItem = 0;
    QString error;

    if(reply->error() != QNetworkReply::NoError)
    {
        qDebug() << "readAll: ", reply->readAll(), "error: ", reply->errorString();
        error = reply->errorString();
    }
    else
    {
        responseItem = inHandlerList[pReq->inHandlerIndex](reply, error, pReq);
    }

    reply->deleteLater();
}

非常感谢您的帮助。

Answer 1

来自documentation :

QByteArray QIODevice::readAll()

This is an overloaded function.

Reads all available data from the device, and returns it as a QByteArray.

This function has no way of reporting errors; returning an empty QByteArray() can mean either that no data was currently available for reading, or that an error occurred.