Qt简单的解析Json数据例子（一）

要解析的json的格式为：

{
    "rootpath": "001", "usernum": 111, "childdep": [ { "depid": "11", "depnum": 20 }, { "depid": "15", "depnum": 23 } ] }

std::map<std::wstring, int> part_depid_num; //这里是吧json的数据直接写成了字符串的形式来完成 QByteArray data = QByteArray("{\"rootpath\":\"001\",\"usernum\":111,\"childdep\":[{\"depid\":\"11\",\"depnum\":20},{\"depid\":\"15\",\"depnum\":23}]}"); //判断字符串转化为QJsonDocument 是否出现了错误 QJsonParseError jsonError;//Qt5新类 QJsonDocument json = QJsonDocument::fromJson(data, &jsonError);//Qt5新类 if (jsonError.error == QJsonParseError::NoError) { if (json.isObject()) { QJsonObject rootObj = json.object(); QString rootpath; int rootusernum; //是否含有key rootpath if (rootObj.contains("rootpath")) { //取出key为rootpath的值 QJsonValue value = rootObj.value("rootpath"); //判断是否是string类型 if (value.isString()) { rootpath = value.toString(); } } if (rootObj.contains("usernum")) { //取出key为usernum的值 QJsonValue value = rootObj.value("usernum"); //判断是否为double类型 if (value.isDouble()) { rootusernum = value.toDouble(); } } part_depid_num[rootpath.toStdWString()] = rootusernum; if (rootObj.contains("childdep")) { QJsonValue valueArray = rootObj.value("childdep"); //判断类型是否为array，并且将array遍历出来 if (valueArray.isArray()) { QJsonArray jsonArray = valueArray.toArray(); for (int i = 0; i < jsonArray.count();i++) { QJsonValue childValue = jsonArray[i]; if (childValue.isObject()) { QString child_depid; QString child_usernum; int child_usern; QJsonObject childObject = childValue.toObject(); if (childObject.contains("depid")) { QJsonValue valueJson = childObject.value("depid"); if (valueJson.isString()) { child_depid = valueJson.toString(); } } if (childObject.contains("depnum")) { QJsonValue valueJson = childObject.value("depnum"); if (valueJson.isDouble()) { child_usern = valueJson.toDouble(); } } if (child_usernum.isEmpty()) { part_depid_num[child_depid.toStdWString()] = child_usern; } } } } } } } //printf(QString::fromStdWString(part_depid_num.begin()->first).toStdString().c_str()); std::map<std::wstring, int> ::iterator it; for (it = part_depid_num.begin(); it != part_depid_num.end();it++) { cout << QString::fromStdWString(it->first).toStdString().c_str()<<endl; }