Qt+JSON简单例子
- Qt+JSON
- example2
- 参考
Qt+JSON
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtDebug>
#include <QJsonObject>
#include <QJsonArray>
#include <QJsonDocument>
#include <QTextCodec>
#include <QFile>
#include <QTextStream>
#include "json.h"MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);init();
}MainWindow::~MainWindow()
{delete ui;
}int MainWindow::init()
{int arr[] = { 1, 2, 3 };double darr[] = { 4.2, 5.2 };bool barr[] = { true, false, true, false };QString value = "str";QJsonObject obj;obj.insert("Name", "Apple");obj.insert("Color", "Red");obj.insert("Weight", 0.2);JSON* json = new JSON();json->writeJson("bool", true);json->writeJson("int", 1);json->writeJson("double", 2.4);// value must be QString, implicit conversion turns string literal into booljson->writeJson("string", value);json->writeJson("str2bool", "str");json->writeJson("bool array", barr, 4);json->writeJson("int array", arr, 3);json->writeJson("double array", darr, 2);json->writeJson("object", obj);qDebug() << json->getJson();QString Passwdfile("hello.json");json->saveJson(Passwdfile);QString json_data = json->toString();ui->textEdit->setText(json_data);//原文链接：https://blog.csdn.net/Cappuccino_jay/article/details/125619033return 0;
}
json.h
#ifndef JSON_H
#define JSON_H#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonParseError>class JSON {
public:JSON();QJsonObject getJson();QJsonObject loadJson(const QString& filepath);void writeJson(const QString key, bool value);void writeJson(const QString key, int value);void writeJson(const QString key, double value);void writeJson(const QString key, QString value);void writeJson(const QString key, bool* array, int length);void writeJson(const QString key, int* array, int length);void writeJson(const QString key, double* array, int length);void writeJson(const QString key, QJsonObject object);bool saveJson(const QString& filepath);QString toString();private:QJsonObject json;
};
#endif // JSON_H
json.cpp
#include <QDebug>
#include <QFile>
#include <QIODevice>#include "json.h"JSON::JSON()
{
}QJsonObject JSON::getJson()
{return json;
}QJsonObject JSON::loadJson(const QString& filepath)
{QFile loadFile(filepath);if (!loadFile.open(QIODevice::ReadOnly))qDebug() << "Unable to load JSON file";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!";QJsonObject rootObj = jsonDoc.object();return rootObj;
}// NOTE: implicit conversion turns string literal into bool
void JSON::writeJson(const QString key, bool value)
{json.insert(key, value);
}void JSON::writeJson(const QString key, int value)
{json.insert(key, value);
}void JSON::writeJson(const QString key, double value)
{json.insert(key, value);
}// value only support QString
void JSON::writeJson(const QString key, QString value)
{json.insert(key, QString(value));
}void JSON::writeJson(const QString key, bool* array, int length)
{QJsonArray arr;for (int i = 0; i < length; i++)arr.append(array[i]);json.insert(key, arr);
}void JSON::writeJson(const QString key, int* array, int length)
{QJsonArray arr;for (int i = 0; i < length; i++)arr.append(array[i]);json.insert(key, arr);
}void JSON::writeJson(const QString key, double* array, int length)
{QJsonArray arr;for (int i = 0; i < length; i++)arr.append(array[i]);json.insert(key, arr);
}void JSON::writeJson(const QString key, QJsonObject object)
{json.insert(key, object);
}bool JSON::saveJson(const QString& filepath)
{QJsonDocument document;document.setObject(json);QFile file(filepath);if (!file.open(QIODevice::WriteOnly | QIODevice::Text)){qDebug() << "Fail to save contents to JSON file";return false;}file.write(document.toJson());return true;
}QString JSON::toString()
{QJsonDocument document;document.setObject(json);QByteArray byteArray = document.toJson(QJsonDocument::Compact);QString str(byteArray);return str;
}
hello.json
{"bool": true,"bool array": [true,false,true,false],"double": 2.4,"double array": [4.2,5.2],"int": 1,"int array": [1,2,3],"object": {"Color": "Red","Name": "Apple","Weight": 0.2},"str2bool": true,"string": "str"
}
example2
json.h
#ifndef JSON_H
#define JSON_H#include <QString>
#include <QJsonDocument>
#include <QJsonParseError>
#include <QJsonObject>
#include <QJsonValue>
#include <QJsonArray>
#include <QFile>
#include <QTextStream>
#include <QDebug>struct Today
{int ID;QString date;char name[32];
};class Json
{
public:Json();
public:int init();bool saveJson(const QString& filepath, QJsonObject &json);private://顺便给结构体给一个变量Today today;
};
#endif // JSON_Hjson.cpp
#include "json.h"Json::Json()
{today.date = "20190911";today.ID = 001;int len = strlen("zhangsan");memcpy(today.name, "zhangsan", len);today.name[len] = '\0';
}int Json::init()
{QJsonObject json;//构建json对象jsonjson.insert("ID", today.ID);json.insert("date", today.date);json.insert("name", today.name);QJsonDocument document;document.setObject(json);QByteArray byte_array = document.toJson(QJsonDocument::Compact);QString json_str(byte_array);QString Passwdfile("hello3.json");saveJson(Passwdfile, json);//原文链接：https://blog.csdn.net/ljwoainia/article/details/100735303return 0;
}bool Json::saveJson(const QString& filepath, QJsonObject &json)
{QJsonDocument document;document.setObject(json);QFile file(filepath);if (!file.open(QIODevice::WriteOnly | QIODevice::Text)){qDebug() << "Fail to save contents to JSON file";return false;}file.write(document.toJson());file.close();qDebug() << "finish to save contents to JSON file" << endl;return true;
}
{"ID": 1,"date": "20190911","name": "zhangsan"
}参考
- Cappuccino-jay【QT】Qt使用QJson生成json文件并保存
- 其实我也恋长安 QT5中如何将数据转换为JSON格式
