#include <QJsonDocument>#include <QJsonObject>#include <QJsonArray>#include <QFile>#include <QDebug>void createJsonFile() {// 创建一个JSON对象 键值对QJsonObject jsonObj;jsonObj["name"] = "John Doe";jsonObj["age"] = 30;jsonObj["email"] = "john.doe@example.com";// 创建一个JSON数组QJsonArray jsonArr;jsonArr.append("C++");jsonArr.append("Python");
jsonArr.append("JavaScript");jsonArr.append(123);// 将数组添加到JSON对象
jsonObj["languages"] = jsonArr;// 将JSON对象转换为JSON文档
QJsonDocument jsonDoc(jsonObj);// 将JSON文档转换为字符串（也可以是压缩格式）
QByteArray jsonData = jsonDoc.toJson(QJsonDocument::Indented);// 将JSON数据写入文件
QFile file("output.json");if (!file.open(QIODevice::WriteOnly)) {qDebug() << "Failed to open file for writing";return;}file.write(jsonData);file.close();}qDebug() << "JSON data saved to output.json";int main() {createJsonFile();return 0;}
#include "widget.h"#include "ui_widget.h"#include <QFile>#include <QJsonArray>#include <QJsonDocument>#include <QJsonObject>Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{}ui->setupUi(this);QJsonObject rootObj;rootObj["cityid"] = "1010100";rootObj["date"]
= "2024-01-23";rootObj["weather"] = "雨夹雪";rootObj["tmp"]
= 3;QJsonArray jsonArray;jsonArray.append("data1");jsonArray.append("data2");jsonArray.append("data3");jsonArray.append(100);rootObj["testArry"] = jsonArray;QJsonDocument jsonDoc(rootObj);QByteArray jsonArry = jsonDoc.toJson();QFile file("D:/QT/test.json");file.open(QIODevice::WriteOnly);file.write(jsonArry);file.close();Widget::~Widget(){delete ui;}
#include "widget.h"#include "ui_widget.h"#include <QFile>#include <QJsonArray>#include <QJsonDocument>#include <QJsonObject>Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget){ui->setupUi(this);QJsonObject rootObj;rootObj["cityid"] = "1010100";rootObj["date"]
= "2024-01-23";rootObj["weather"] = "雨夹雪";
= 3;rootObj["tmp"]
//Json数组
QJsonArray jsonArray;jsonArray.append("data1");jsonArray.append("data2");jsonArray.append("data3");jsonArray.append(100);rootObj["testArry"] = jsonArray;QJsonObject alarmObj;alarmObj["alamType"] = "雪灾";alarmObj["alamLeve"] = "黄色";alarmObj["alamTitle"] = "福州市警告老陈多穿点衣服";rootObj["alam"] = alarmObj;QJsonObject day0;day0["day"] = "星期一";day0["wea"] = "晴";day0["tem"] = 5.7;QJsonObject day1;day1["day"] = "星期二";day1["wea"] = "晴";day1["tem"] = 7;QJsonObject day2;day2["day"] = "星期三";day2["wea"] = "多云";day2["tem"] = 17;QJsonArray dayArray;dayArray.append(day0);dayArray.append(day1);dayArray.append(day2);rootObj["days"] = dayArray;//通过QJsonDocument把JSON数据转换成QByteArrayQJsonDocument jsonDoc(rootObj);QByteArray jsonArry = jsonDoc.toJson();QFile file("D:/QT/test.json");file.open(QIODevice::WriteOnly);file.write(jsonArry);file.close();}Widget::~Widget(){delete ui;}
#include <QJsonDocument>#include <QJsonObject>#include <QJsonArray>#include <QDebug>void parseJson() {// JSON字符串/*R 是用于定义原始字符串字面量（Raw String Literal）的标记。在C++中，原始字符串字面量是一种方便的语法，用于创建包含多行文本和特殊字符的字符串，而无需转义。R"("chenlichen")"*/QString testStr = "chenli\"c";QString jsonString = R"({"name": "John Doe","age": 30,"email": "john.doe@example.com","skills": ["C++", "Python", "JavaScript"]})";/*jsonString = "{\n"" \"name\": \"John Doe\",\n"" \"age\": 30\n""}";*/// 将JSON字符串转换为QJsonDocumentQJsonDocument jsonDoc = QJsonDocument::fromJson(jsonString.toUtf8());// 检查JSON文档是否包含一个对象if (!jsonDoc.isNull() && jsonDoc.isObject()) {// 获取JSON对象QJsonObject jsonObj = jsonDoc.object();
// 访问对象的键值
QString name = jsonObj["name"].toString();int age = jsonObj["age"].toInt();QString email = jsonObj["email"].toString();qDebug() << "Name:" << name;qDebug() << "Age:" << age;qDebug() << "Email:" << email;}// 处理JSON数组
if (jsonObj.contains("skills") && jsonObj["skills"].isArray()) {QJsonArray skillsArray = jsonObj["skills"].toArray();for (const QJsonValue &value : skillsArray) {qDebug() << "Skill:" << value.toString();}}} else {qDebug() << "Invalid JSON...";}int main() {parseJson();return 0;}
#include <QJsonDocument>#include <QJsonObject>#include <QMap>#include <QDebug>void parseJsonToMap() {// JSON字符串
QString jsonString = R"({"name": "John Doe","age": "30","email": "john.doe@example.com"})";// 将JSON字符串转换为QJsonDocumentQJsonDocument jsonDoc = QJsonDocument::fromJson(jsonString.toUtf8());// 准备一个QMap来存储解析的数据
QMap<QString, QString> dataMap;// 解析JSON对象并填充QMapif (!jsonDoc.isNull() && jsonDoc.isObject()) {QJsonObject jsonObj = jsonDoc.object();for (auto key : jsonObj.keys()) {dataMap[key] = jsonObj.value(key).toString();}} else {qDebug() << "Invalid JSON...";}// 打印QMap内容
for (auto key : dataMap.keys()) {qDebug() << key << ":" << dataMap[key];}}int main() {parseJsonToMap();return 0;}
#include "widget.h"#include "ui_widget.h"#include <QFile>#include <QJsonDocument>#include <QJsonObject>#include <QDebug>#include <QJsonArray>Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget){ui->setupUi(this);//第一步：读取JSON文件保存到QByteArray中
QFile file("D:/QT/test.json");file.open(QIODevice::ReadOnly);QByteArray rawData = file.readAll();file.close();//第二步：把QByteArray转成JSONDocQJsonDocument jsonDoc = QJsonDocument::fromJson(rawData);if( !jsonDoc.isNull() && jsonDoc.isObject()){//第三步：把JsonDoc转成JsonObjQJsonObject jsonRoot = jsonDoc.object();//第四步：如果解析普通键值对，通过“下表键”来获取值
QString strW
= jsonRoot["weather"].toString();QString strCityId = jsonRoot["cityid"].toString();int tempretrue = jsonRoot["tmp"].toInt();qDebug() << strW;qDebug() << strCityId;qDebug() << QString::number(tempretrue);//第五步：判读是否是一个数组if(jsonRoot.contains("testArry") && jsonRoot["testArry"].isArray()){qDebug() << "array";//如果是数组，转换成JSON数组QJsonArray testArray = jsonRoot["testArry"].toArray();//遍历数组，访问每一项for(QJsonValue val : testArray){//QJsonValue的type函数返回数据类型，根据不同的数据类型处理数据// QJsonValue::Type t = val.type();switch (val.type()) {case QJsonValue::Double:qDebug() << QString::number(val.toDouble());break;case QJsonValue::String:qDebug() << val.toString();break;case QJsonValue::Object:break;}}}//第六步：判断某个键对应的值，是否是一个json对象if(jsonRoot.contains("alam") && jsonRoot["alam"].isObject()){//转成Json对象后处理QJsonObject alamObj = jsonRoot["alam"].toObject();qDebug() << alamObj["alamLeve"].toString();qDebug() << alamObj["alamTitle"].toString();qDebug() << alamObj["alamType"].toString();}if(jsonRoot.contains("days") && jsonRoot["days"].isArray()){QJsonArray dayArray = jsonRoot["days"].toArray();for(QJsonValue val : dayArray){//if(val.type() ==QJsonValue::Object ){if(val.isObject()){QJsonObject obj = val.toObject();qDebug() << obj["day"].toString();qDebug() << QString::number(obj["tem"].toDouble());qDebug() << obj["wea"].toString();}}}}}Widget::~Widget(){delete ui;}
