Qt中的JSON使用QVariantMap

Question

我想在symbian应用程序中解析此JSON输出:

[
    {"ID":"9","titel":"wouter","plaatsID":"2616","prio":"3"},
    {"ID":"8","titel":"pasta","plaatsID":"3780","prio":"3"},
    {"ID":"6","titel":"Muts prikken","plaatsID":"3780","prio":"2"
    {"ID":"5","titel":"doorplannen","plaatsID":"3840","prio":"2"}
    {"ID":"4","titel":"Gasfles","plaatsID":"3780","prio":"2"}
]

为此,我编写了以下代码,但我无法读取数据.其他单个JSON输出它工作正常,但多输出不起作用:

     void start::finishedSlot(QNetworkReply * reply)
    {
        // Reading attributes of the reply
        // e.g. the HTTP status code
        reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
    reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
    // see CS001432 on how to handle this
    // no error received?
    if (reply->error() == QNetworkReply::NoError)
    {
            QByteArray data = reply->readAll();
        bool ok;
        QVariantMap result = Json::parse(QString(data), ok).toMap();

        if(!ok) {
            qFatal("An error occurred during parsing");
            exit(1);
        }
        QMapIterator<QString, int> i(result);
        while (i.hasNext()) {
            i.next();
            cout << i.key() << ": " << i.value() << endl;
        }

    ui->log->setText("het gaat goed");
    }
    // Some http error received
    else
    {
     ui->log->setText("gaat NIET goed");
    }
    delete reply;
}

Answer 1

在Qt 5中,它支持JSON数据.

"Qt提供了对JSON数据处理的支持.JSON是一种编码从Javascript派生的对象数据的格式,但现在广泛用作互联网上的数据交换格式.Qt中的JSON支持提供了一个易于使用的C++ API来解析,修改和保存JSON数据.它还支持以二进制格式保存这些数据,这种格式可以直接访问mmap,访问速度非常快.有关JSON数据格式的更多细节可以在RFC-4627中找到."

http://qt-project.org/doc/qt-5/json.html

如果你需要的话,我认为将它们移植到Qt 4并不困难.

至少你可以在https://github.com/qtproject/qtbase/tree/5.3/src/corelib/json找到代码

有人将QJson*从5移到4 :(已添加2013-07-02) https://github.com/5in4/qjson-backport

注意:2012-11-30

其他人也指出可以使用QtScript来解析JSON数据.如果您可以阅读中文(如果不能,请谷歌翻译):http://www.cuteqt.com/blog/？p = 2261(此网站暂时停用,忘记通过谷歌阅读器备份,以及GR也死... 2013-07-02)

Answer 2

void parse_links(const QScriptValue & value, QList<Link> & cbk_links)\n{\n    QList<QVariantMap> list;\n    qScriptValueToSequence(value,list);\n    foreach(auto item, list)\n    {\n        Link link;\n\n        link.yawDeg = item.value("yawDeg").toFloat();\n        link.panoId = item.value("panoId").toString();\n        link.road_argb = item.value("road_argb").toString();\n        link.description = item.value("description").toString();\n        link.scene = item.value("scene").toInt();\n\n        cbk_links.append(link);\n    }\n}\n

\n\n

用于传递：

\n\n

"Links":    [\n            {   "yawDeg":"18.49",\n                "panoId":"Voal3KQo5FNL67hq7tA8nA",\n                "road_argb":"0x80ffffff",\n                "description":"Knuth-Wintherfeldts All\xc3\xa9",\n                "scene":"0"\n            },          {   "yawDeg":"198.49",\n                "panoId":"6RCsAsNoawmh98eOOs7Wzw",\n                "road_argb":"0x80ffffff",\n                "description":"Knuth-Wintherfeldts All\xc3\xa9",\n                "scene":"0"\n            }\n        ]\n

\n