原文地址：

https://blog.csdn.net/hp_cpp/article/details/80338116

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Json文件是這樣：

{"first fruit":{"describe":"an apple","icon":"appleIcon","name":"apple"},"second fruit":{"describe":"an orange","icon":"orangeIcon","name":"orange"},"three fruit array":["eat 0","eat 1","eat 2","eat 3","eat 4"] }

存放在本地磁盤。?
利用QJson可以方便的進行解析。

QFile loadFile("D:\\1.json");if(!loadFile.open(QIODevice::ReadOnly)){qDebug() << "could't open projects json";return;}QByteArray allData = loadFile.readAll();loadFile.close();QJsonParseError json_error;QJsonDocument jsonDoc(QJsonDocument::fromJson(allData, &json_error));if(json_error.error != QJsonParseError::NoError){qDebug() << "json error!";return;}QJsonObject rootObj = jsonDoc.object();//輸出所有key，這一步是非必須的，放最后的話，你可能讀不到任何keyQStringList keys = rootObj.keys();for(int i = 0; i < keys.size(); i++){qDebug() << "key" << i << " is:" << keys.at(i);}//因為是預先定義好的JSON數據格式，所以這里可以這樣讀取if(rootObj.contains("first fruit")){QJsonObject subObj = rootObj.value("first fruit").toObject();qDebug() << "describe is:" << subObj["describe"].toString();qDebug() << "icon is:" << subObj["icon"].toString();qDebug() << "name is:" << subObj["name"].toString();}if(rootObj.contains("second fruit")){QJsonObject subObj = rootObj.value("second fruit").toObject();qDebug() << "describe is:" << subObj.value("describe").toString();qDebug() << "icon is:" << subObj.value("icon").toString();qDebug() << "name is:" << subObj.value("name").toString();}if(rootObj.contains("three fruit array")){QJsonArray subArray = rootObj.value("three fruit array").toArray();for(int i = 0; i< subArray.size(); i++){qDebug() << i<<" value is:" << subArray.at(i).toString();}}

需要包含的頭文件：

#include <QJsonDocument> #include <QJsonParseError> #include <QFile> #include <QJsonObject> #include <QDebug> #include <QJsonArray>

運行結果：

key 0 ?is: "first fruit" key 1 ?is: "second fruit" key 2 ?is: "three fruit array" describe is: "an apple" icon is: "appleIcon" name is: "apple" describe is: "an orange" icon is: "orangeIcon" name is: "orange" 0 ?value is: "eat 0" 1 ?value is: "eat 1" 2 ?value is: "eat 2" 3 ?value is: "eat 3" 4 ?value is: "eat 4"

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