当前位置：网站首页>[QT] QT uses qjson to generate JSON files and save them
[QT] QT uses qjson to generate JSON files and save them
2022-07-05 23:58:00 【Cappuccino-jay】
Sample 1:
#include <QJsonDocument>
#include <QJsonParseError>
#include <QFile>
#include <QJsonObject>
#include <QDebug>
#include <QJsonArray>
#include <QByteArray>
void createJson()
{
QVariantHash data;
QVariantHash subData1;
subData1.insert("name", "apple");
subData1.insert("icon", "appleIcon");
subData1.insert("describe", "an apple");
data.insert("first fruit", subData1);
QVariantHash subData2;
subData2.insert("name", "orange");
subData2.insert("icon", "orangeIcon");
subData2.insert("describe", "an orange");
data.insert("second fruit", subData2);
QJsonArray array1;
for (int i = 0; i < 5; i++)
{
array1.insert(i, QString::fromLocal8Bit("eat %1").arg(i));
}
data.insert("three fruit array", array1);
QJsonObject rootObj = QJsonObject::fromVariantHash(data);
QJsonDocument document;
document.setObject(rootObj);
QByteArray byte_array = document.toJson(QJsonDocument::Compact);
QString json_str(byte_array);
// Fill in the path according to the actual
QFile file("D:\\1.json");
if (!file.open(QIODevice::ReadWrite | QIODevice::Text))
{
qDebug() << "file error!";
}
QTextStream in(&file);
in << json_str;
file.close(); // close file
}
Sample 2：
Create a new one QT Empty item ：
#include <QCoreApplication>
#include <QJsonObject> // { }
#include <QJsonArray> // [ ]
#include <QJsonDocument> // analysis Json
#include <QJsonValue> // int float double bool null { } [ ]
#include <QJsonParseError>
#include <QDebug>
#include <QFile>
#include <QTextStream>
#pragma execution_character_set("utf-8") // qt Support to display Chinese
// encapsulation Json
void createJson() {
/* * "interest": { * "basketball": " Basketball ", * "badminton": " badminton " * }, */
// Definition { } object
QJsonObject interestObj;
// Insert elements , Corresponding key value pairs
interestObj.insert("basketball", " Basketball ");
interestObj.insert("badminton", " badminton ");
/* * "color": [ "black", "white"], */
// Definition [ ] Array
QJsonArray colorArray;
// Add elements to the array
colorArray.append("black");
colorArray.append("white");
/* * "like": [ * { "game": " War Within Three Kingdoms ", "price": 58.5 }, * { "game": " Island soldiers ", "price": 66.65 } * ], */
// Definition { } object
QJsonObject likeObject1;
likeObject1.insert("game", " War Within Three Kingdoms ");
likeObject1.insert("price", 58.5);
QJsonObject likeObject2;
likeObject2.insert("game", " Island soldiers ");
likeObject2.insert("price", 66.65);
// Definition [ ] object
QJsonArray likeArray;
likeArray.append(likeObject1);
likeArray.append(likeObject2);
/* * "languages": { * "serialOne": { "language": " chinese ", "grade": 10 }, * "serialTwo": { "language": " English ", "grade": 6 } * }, */
// Definition { } object
QJsonObject language1;
language1.insert("language", " chinese ");
language1.insert("grade", 10);
QJsonObject language2;
language2.insert("language", " English ");
language2.insert("grade", 6);
QJsonObject languages;
// take { } Insert { } in
languages.insert("serialOne", language1);
languages.insert("serialTwo", language2);
// Define the root node That is, the outermost layer { }
QJsonObject rootObject;
// Insert elements
rootObject.insert("name", " Lao Wang ");
rootObject.insert("age", 26);
rootObject.insert("interest", interestObj);
rootObject.insert("color", colorArray);
rootObject.insert("like", likeArray);
rootObject.insert("languages", languages);
rootObject.insert("vip", true);
rootObject.insert("address", QJsonValue::Null);
// take json The data in the object is converted into a string
QJsonDocument doc;
// take object Set as the main object of this document
doc.setObject(rootObject);
// Json Save the string to json In the document
QFile file("../Json/js.json");
if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
qDebug() << "can't open error!";
return;
}
QTextStream stream(&file);
stream.setCodec("UTF-8"); // Set the write encoding to UTF8
// write file
stream << doc.toJson();
file.close();
}
// analysis Json
void analysisJson() {
QFile file("../Json/js.json");
if (!file.open(QFile::ReadOnly | QFile::Text)) {
qDebug() << "can't open error!";
return;
}
// Read the entire contents of the file
QTextStream stream(&file);
stream.setCodec("UTF-8"); // Set the read code to UTF8
QString str = stream.readAll();
file.close();
/* analysis Json */
// QJsonParseError Class is used in JSON Error reported during parsing .
QJsonParseError jsonError;
// take json It can be interpreted as UTF-8 Coded json file , And create a QJsonDocument.
// If the parsing is successful , return QJsonDocument object , Otherwise return to null
QJsonDocument doc = QJsonDocument::fromJson(str.toUtf8(), &jsonError);
// Judge whether the parsing fails
if (jsonError.error != QJsonParseError::NoError && !doc.isNull()) {
qDebug() << "Json Format error ！" << jsonError.error;
return;
}
// Get root { }
QJsonObject rootObj = doc.object();
// Get value from key
QJsonValue nameValue = rootObj.value("name");
qDebug() << "name = " << nameValue.toString();
QJsonValue ageValue = rootObj.value("age");
qDebug() << "age = " << ageValue.toInt();
// Parse object { }
QJsonValue interestValue = rootObj.value("interest");
// Judge whether it is object type
if (interestValue.type() == QJsonValue::Object) {
// Convert to QJsonObject type
QJsonObject interestObj = interestValue.toObject();
QJsonValue basketballValue = interestObj.value("basketball");
qDebug() << "basketball = " << basketballValue.toString();
QJsonValue badmintonValue = interestObj.value("badminton");
qDebug() << "badminton = " << badmintonValue.toString();
}
// Parsing arrays [ ]
QJsonValue colorValue = rootObj.value("color");
// Judge whether it is Array type
if (colorValue.type() == QJsonValue::Array) {
// Convert to QJsonArray type
QJsonArray colorArray = colorValue.toArray();
for (int i = 0; i < colorArray.size(); i++) {
QJsonValue color = colorArray.at(i);
qDebug() << "color = " << color.toString();
}
}
// Parse the objects in the array [ { } ]
QJsonValue likeValue = rootObj.value("like");
if (likeValue.type() == QJsonValue::Array) {
QJsonArray likeArray = likeValue.toArray();
for (int i = 0; i < likeArray.count(); i++) {
QJsonValue likeValueChild = likeArray.at(i);
if (likeValueChild.type() == QJsonValue::Object) {
QJsonObject likeObj = likeValueChild.toObject();
QJsonValue gameLikeValue = likeObj.value("game");
qDebug() << "game = " << gameLikeValue.toString();
QJsonValue priceLikeValue = likeObj.value("price");
qDebug() << "price = " << priceLikeValue.toDouble();
}
}
}
// analysis object in object { { } }
QJsonValue languagesValue = rootObj.value("languages");
if (languagesValue.type() == QJsonValue::Object) {
QJsonObject languagesObj = languagesValue.toObject();
QJsonValue serialOneValue = languagesObj.value("serialOne");
if (serialOneValue.type() == QJsonValue::Object) {
QJsonObject serialOneObj = serialOneValue.toObject();
QJsonValue languageValue = serialOneObj.value("language");
qDebug() << "language = " << languageValue.toString();
QJsonValue gradeValue = serialOneObj.value("grade");
qDebug() << "grade = " << gradeValue.toInt();
}
QJsonValue serialTwoValue = languagesObj.value("serialTwo");
if (serialTwoValue.type() == QJsonValue::Object) {
QJsonObject serialTwoObj = serialTwoValue.toObject();
QJsonValue languageValue = serialTwoObj.value("language");
qDebug() << "language = " << languageValue.toString();
QJsonValue gradeValue = serialTwoObj.value("grade");
qDebug() << "grade = " << gradeValue.toInt();
}
}
// analysis bool type
QJsonValue vipValue = rootObj.value("vip");
qDebug() << "vip = " << vipValue.toBool();
// analysis null type
QJsonValue addressValue = rootObj.value("address");
if (addressValue.type() == QJsonValue::Null) {
qDebug() << "address = " << "null";
}
}
// modify Json data
void alterJson() {
/* If you want to modify it, just rewrite it again and overwrite it */
QFile readFile("../Json/js.json");
if (!readFile.open(QFile::ReadOnly | QFile::Truncate)) {
qDebug() << "can't open error!";
return;
}
// Read the entire contents of the file
QTextStream readStream(&readFile);
readStream.setCodec("UTF-8"); // Set the read code to UTF8
QString str = readStream.readAll();
readFile.close();
/* modify Json */
// QJsonParseError Class is used in JSON Error reported during parsing .
QJsonParseError jsonError;
// take json It can be interpreted as UTF-8 Coded json file , And create a QJsonDocument.
// If the parsing is successful , return QJsonDocument object , Otherwise return to null
QJsonDocument doc = QJsonDocument::fromJson(str.toUtf8(), &jsonError);
if (jsonError.error != QJsonParseError::NoError && !doc.isNull()) {
qDebug() << "Json Format error ！" << jsonError.error;
return;
}
// Get root { }
QJsonObject rootObj = doc.object();
// modify name attribute
rootObj["name"] = " Lao Li ";
rootObj["vip"] = false;
// Modify array [] The elements in
QJsonValue colorValue = rootObj.value("color");
if (colorValue.type() == QJsonValue::Array) {
QJsonArray colorArray = colorValue.toArray();
// Modify the values in the array
colorArray.replace(0, "blue");
colorArray.replace(1, "green");
// Assignment overrides the original array attribute
rootObj["color"] = colorArray;
}
// modify { } The value in
QJsonValue interestValue = rootObj.value("interest");
if (interestValue.type() == QJsonValue::Object) {
QJsonObject interestObject = interestValue.toObject();
interestObject["badminton"] = " Table Tennis ";
interestObject["basketball"] = " football ";
rootObj["interest"] = interestObject;
}
// modify { { } } The value in
QJsonValue languagesValue = rootObj.value("languages");
if (languagesValue.type() == QJsonValue::Object) {
QJsonObject languagesObj = languagesValue.toObject();
// Find the first one inside { }
QJsonValue serialOneValue = languagesObj.value("serialOne");
if (serialOneValue.type() == QJsonValue::Object) {
QJsonObject serialOneObj = serialOneValue.toObject();
serialOneObj["grade"] = "20";
languagesObj["serialOne"] = serialOneObj;
}
// Find the second inside { }
QJsonValue serialTwoValue = languagesObj.value("serialTwo");
if (serialTwoValue.type() == QJsonValue::Object) {
QJsonObject serialTwoObj = serialTwoValue.toObject();
serialTwoObj["grade"] = "10";
serialTwoObj["language"] = " Cantonese ";
languagesObj["serialTwo"] = serialTwoObj;
}
rootObj["languages"] = languagesObj;
}
// modify [ { } ]
QJsonValue likeValue = rootObj.value("like");
if (likeValue.type() == QJsonValue::Array) {
QJsonArray likeArray = likeValue.toArray();
// Get the corresponding according to the index { }
QJsonObject obj1 = likeArray[0].toObject();
obj1["game"] = " Happy game ";
obj1["price"] = 88.8;
QJsonObject obj2 = likeArray[1].toObject();
obj2["game"] = " Happy bullfight ";
obj2["price"] = 77.7;
// Replace overlay
likeArray.replace(0, obj1);
likeArray.replace(1, obj2);
rootObj["like"] = likeArray;
}
// take object Set as the main object of this document
doc.setObject(rootObj);
// Rewrite open file , Overwrite the original file , Achieve the effect of deleting all the contents of the file
QFile writeFile("../Json/js.json");
if (!writeFile.open(QFile::WriteOnly | QFile::Truncate)) {
qDebug() << "can't open error!";
return;
}
// Write the modified content to the file
QTextStream wirteStream(&writeFile);
wirteStream.setCodec("UTF-8"); // Set the read code to UTF8
wirteStream << doc.toJson(); // write file
writeFile.close(); // Close file
}
// Delete Json
void delJson() {
QFile readFile("../Json/js.json");
if (!readFile.open(QFile::ReadOnly | QFile::Truncate)) {
qDebug() << "can't open error!";
return;
}
// Read the entire contents of the file
QTextStream readStream(&readFile);
readStream.setCodec("UTF-8"); // Set the read code to UTF8
QString str = readStream.readAll();
readFile.close();
/* modify Json */
// QJsonParseError Class is used in JSON Error reported during parsing .
QJsonParseError jsonError;
// take json It can be interpreted as UTF-8 Coded json file , And create a QJsonDocument.
// If the parsing is successful , return QJsonDocument object , Otherwise return to null
QJsonDocument doc = QJsonDocument::fromJson(str.toUtf8(), &jsonError);
if (jsonError.error != QJsonParseError::NoError && !doc.isNull()) {
qDebug() << "Json Format error ！" << jsonError.error;
return;
}
// Get root { }
QJsonObject rootObj = doc.object();
// Delete age
rootObj.remove("age");
// Delete array [] The elements in
QJsonValue colorValue = rootObj.value("color");
if (colorValue.type() == QJsonValue::Array) {
QJsonArray colorArray = colorValue.toArray();
// Delete the array with index 1 Value
colorArray.removeAt(1);
// Assignment overrides the original array attribute
rootObj["color"] = colorArray;
}
// Delete { } The value in
QJsonValue interestValue = rootObj.value("interest");
if (interestValue.type() == QJsonValue::Object) {
QJsonObject interestObject = interestValue.toObject();
// The delete key is basketball Attribute element of
interestObject.remove("basketball");
rootObj["interest"] = interestObject;
}
// Delete { { } } The value in
QJsonValue languagesValue = rootObj.value("languages");
if (languagesValue.type() == QJsonValue::Object) {
QJsonObject languagesObj = languagesValue.toObject();
// The delete key is serialTwo The object of { }
languagesObj.remove("serialTwo");
rootObj["languages"] = languagesObj;
}
// Delete [ ] Medium { }
QJsonValue likeValue = rootObj.value("like");
if (likeValue.type() == QJsonValue::Array) {
QJsonArray likeArray = likeValue.toArray();
// Delete index as 1 The values in the array
likeArray.removeAt(1);
rootObj["like"] = likeArray;
}
// Delete [ ]
rootObj.remove("color");
// Delete { }
rootObj.remove("interest");
// take object Set as the main object of this document
doc.setObject(rootObj);
// Rewrite open file , Overwrite the original file , Achieve the effect of deleting all the contents of the file
QFile writeFile("../Json/js.json");
if (!writeFile.open(QFile::WriteOnly | QFile::Truncate)) {
qDebug() << "can't open error!";
return;
}
// Write the modified content to the file
QTextStream wirteStream(&writeFile);
wirteStream.setCodec("UTF-8"); // Set the read code to UTF8
wirteStream << doc.toJson(); // write file
writeFile.close(); // Close file
}
int main(int argc, char *argv[]) {
QCoreApplication a(argc, argv);
createJson();
analysisJson();
alterJson();
delJson();
return a.exec();
}
remarks ： Specified encoding #pragma execution_character_set(“utf-8”) // qt Support to display Chinese
Sample 3：（ One json Object contains multiple arrays ）
1、cjsonio.h
#ifndef CJSONIO_H
#define CJSONIO_H
#include <QHash>
class CJsonIO
{
public:
CJsonIO();
~CJsonIO();
static CJsonIO * GetInstance();
bool ReadJson(const QString& dir, const QString& fileName);
bool WriteJson(const QString& dir, const QString& fileName);
void PrintCurJson();
void Init();
QStringList GetValue(QString key);
private:
static CJsonIO m_jsonIO;
QHash<QString, QStringList> m_hash; // Store the current json
QHash<QString, QStringList> m_defaultHash; // Store default json
};
#endif // CJSONIO_H
2、cjsonio.cpp
#include "cjsonio.h"
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonParseError>
#include <QJsonArray>
#include <QFile>
#include <QDebug>
CJsonIO CJsonIO::m_jsonIO;
CJsonIO::CJsonIO() :
m_hash(),m_defaultHash()
{
this->Init();
}
CJsonIO::~CJsonIO()
{
}
CJsonIO *CJsonIO::GetInstance()
{
return &m_jsonIO;
}
bool CJsonIO::ReadJson(const QString &dir, const QString &fileName)
{
bool result = false;
do
{
//read document
QString file = dir + fileName;
QFile loadFile(file);
if (!loadFile.open(QIODevice::ReadOnly))
{
qDebug() << "could't open projects json";
break;
}
QByteArray allData = loadFile.readAll();
loadFile.close();
//set QJsonDocument
QJsonParseError jsonError;
QJsonDocument document = QJsonDocument::fromJson(allData, &jsonError); // Function description ： analysis UTF-8 Coded JSON Document and create QJsonDocument.
if (document.isNull() || (jsonError.error != QJsonParseError::NoError))
{
qDebug() << "document error";
break;
}
if (jsonError.error == QJsonParseError::IllegalUTF8String) // Illegal in input UTF8 Sequence
{
qDebug() << "An illegal UTF8 sequence occurred in the input";
break;
}
if (!document.isObject())
{
qDebug() << "document is not object";
break;
}
//read QJson
QHash<QString, QStringList> indexHash;
QStringList indexList;
QStringList keys = document.object().keys();
QJsonObject object = document.object();
int keySize = keys.size();
for (int i = 0; i < keySize; ++i)
{
QString strKey = keys.at(i);
indexList.clear();
if (object.contains(strKey))
{
QJsonValue value = object.value(strKey);
if (value.isArray())
{
QJsonArray array = value.toArray();
int arrSize = array.size();
for (int i = 0; i < arrSize; ++i)
{
QJsonValue arrValue = array.at(i);
if (arrValue.isString())
{
QString strValue = arrValue.toString();
indexList.push_back(strValue);
}
}
}
indexHash.insert(strKey, indexList);
}
}
this->m_hash = indexHash;
this->m_defaultHash = indexHash;
result = true;
}while(false);
return result;
}
bool CJsonIO::WriteJson(const QString &dir, const QString &fileName)
{
bool result = false;
do
{
//set QJson
QJsonObject jsonObject;
QHash<QString,QStringList>::const_iterator iter = this->m_hash.constBegin();
while (iter != this->m_hash.constEnd())
{
QJsonArray jsonArray;
QString key = iter.key();
QStringList valueList = iter.value();
QStringList::const_iterator listIter = valueList.begin();
while (listIter != valueList.end())
{
jsonArray.append(*listIter);
++listIter;
}
jsonObject.insert(key, QJsonValue(jsonArray));
++iter;
}
//set QJsonDocument
QJsonDocument doc(jsonObject);
QByteArray byteArray = doc.toJson();
//write document
QString strFile = dir + fileName;
QFile loadFile(strFile);
if (!loadFile.open(QIODevice::WriteOnly))
{
qDebug() << "could't open projects json";
break;
}
loadFile.write(byteArray);
loadFile.close();
result = true;
}while(false);
return result;
}
void CJsonIO::PrintCurJson()
{
QHash<QString,QStringList>::const_iterator iter = this->m_hash.constBegin();
while (iter != this->m_hash.constEnd())
{
QString key = iter.key();
QStringList valueList = iter.value();
qDebug() << "key:" << key << ": ";
QStringList::const_iterator listIter = valueList.begin();
while (listIter != valueList.end())
{
qDebug() << "value:" << *listIter;
++listIter;
}
++iter;
}
}
QStringList CJsonIO::GetValue(QString key)
{
QStringList valueList;
QHash<QString, QStringList>::const_iterator iter = this->m_hash.constBegin();
while (iter != this->m_hash.constEnd())
{
QString hashKey = iter.key();
if (hashKey == key)
{
valueList = iter.value();
}
++iter;
}
return valueList;
}
void CJsonIO::Init()
{
this->ReadJson("../Json/","read.json");
}
3、main.cpp
#include "cjsonio.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
CJsonIO *json = CJsonIO::GetInstance();
QString dir = "../Json/";
QString readFile = "read.json";
QString writeFile = "write.json";
json->ReadJson(dir, readFile);
json->WriteJson(dir, writeFile);
json->PrintCurJson();
return a.exec();
}
Sample 4：
JSON encapsulation ： It includes JSON The read 、 analysis 、 Generate and save these basic functions
1、json.h file
#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
2、json.cpp file
#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)) {
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;
}
3、main.cpp file （ The test data ）
#include <QApplication>
#include <QDebug>
#include <QHBoxLayout>
#include <QLabel>
#include "json.h"
#include "mainwindow.h"
int main(int argc, char* argv[])
{
QApplication a(argc, argv);
MainWindow w;
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 bool
json->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();
json->saveJson("../test.json");
QWidget* widget = new QWidget();
QLabel* label = new QLabel();
label->setText(json->toString());
QHBoxLayout* hBoxLayout = new QHBoxLayout();
hBoxLayout->addWidget(label);
widget->setLayout(hBoxLayout);
w.setCentralWidget(widget);
w.show();
return a.exec();
}
4、 Generated JSON Sample file
{
"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"
}
remarks ：mainwindow.h and mainwindow.cpp I'm going to use it directly here Qt Generated by default . The code above needs to pay attention to ： about json->writeJson("str2bool", "str"); It will print out "str2bool":true, This is because the string literal will be implicitly "str" Convert to bool type , If you need to print out a string , You must explicitly set the corresponding value to QString type , therefore json->writeJson("string", value); It will print out the expected "string":"str".
Reference documents ：
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