C/C++ QT实现解析JSON文件的示例代码

{ "blog": "https://www.cnblogs.com/lyshark", "enable": true, "status": 1024, "GetDict": {"address":"192.168.1.1","username":"root","password":"123456","update":"2020-09-26"}, "GetList": [1,2,3,4,5,6,7,8,9,0], "ObjectInArrayJson": { "One": ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"], "Two": ["Sunday","Monday","Tuesday"] }, "ArrayJson": [ ["192.168.1.1","root","22"], ["192.168.1.2","root","23"], ["192.168.1.3","root","24"], ["192.168.1.4","root","25"], ["192.168.1.5","root","26"] ], "ObjectJson": [ {"address":"192.168.1.1","username":"admin"}, {"address":"192.168.1.2","username":"root"}, {"address":"192.168.1.3","username":"lyshark"} ], "ObjectArrayJson": [ {"uname":"root","ulist":[1,2,3,4,5]}, {"uname":"lyshark","ulist":[11,22,33,44,55,66,77,88,99]} ], "NestingObjectJson": [ { "uuid": "1001", "basic": { "lat": "12.657", "lon": "55.789" } }, { "uuid": "1002", "basic": { "lat": "31.24", "lon": "25.55" } } ], "ArrayNestingArrayJson": [ { "telephone": "1323344521", "path": [ [ 11.5,22.4,56.9 ], [ 19.4,34.6,44.7 ] ] } ] } 

// 读取JSON文本 // https://www.cnblogs.com/lyshark QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // 修改根节点下的子节点 root["blog"] = "https://www.baidu.com"; root["enable"] = false; root["status"] = 2048; // 将object设置为本文档的主要对象 root_document.setObject(root); // 紧凑模式输出 // https://www.cnblogs.com/lyshark QByteArray root_string_compact = root_document.toJson(QJsonDocument::Compact); std::cout << "紧凑模式: " << root_string_compact.toStdString() << std::endl; // 规范模式输出 QByteArray root_string_indented = root_document.toJson(QJsonDocument::Indented); std::cout << "规范模式: " << root_string_indented.toStdString() << std::endl; // 分别写出两个配置文件 writeonly_string("d:/indented_config.json",root_string_indented); writeonly_string("d:/compact_config.json",root_string_compact); return a.exec(); } 

// 读取JSON文本 // https://www.cnblogs.com/lyshark QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // -------------------------------------------------------------------- // 修改GetDict对象内容 // -------------------------------------------------------------------- // 找到对象地址,并修改 QJsonObject get_dict_ptr = root.find("GetDict").value().toObject(); // 修改对象内存数据 get_dict_ptr["address"] = "127.0.0.1"; get_dict_ptr["username"] = "lyshark"; get_dict_ptr["password"] = "12345678"; get_dict_ptr["update"] = "2021-09-25"; // 赋值给根 root["GetDict"] = get_dict_ptr; // 将对象设置到根 root_document.setObject(root); // 规范模式 QByteArray root_string_indented = root_document.toJson(QJsonDocument::Indented); // 写配置文件 writeonly_string("d:/indented_config.json",root_string_indented); // -------------------------------------------------------------------- // 修改GetList数组内容 // -------------------------------------------------------------------- // 找到数组并修改 QJsonArray get_list_ptr = root.find("GetList").value().toArray(); // 替换指定下标的数组元素 get_list_ptr.replace(0,22); get_list_ptr.replace(1,33); // 将当前数组元素直接覆盖到原始位置 QJsonArray item = {"admin","root","lyshark"}; get_list_ptr = item; // 设置到原始数组 root["GetList"] = get_list_ptr; root_document.setObject(root); QByteArray root_string_list_indented = root_document.toJson(QJsonDocument::Indented); writeonly_string("d:/indented_config.json",root_string_list_indented); return a.exec(); } 

// 读取JSON文本 QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 // https://www.cnblogs.com/lyshark bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // -------------------------------------------------------------------- // 修改对象中的列表 // -------------------------------------------------------------------- // 找到对象地址并修改 QJsonObject get_dict_ptr = root.find("ObjectInArrayJson").value().toObject(); // 迭代器输出对象中的数据 QJsonObject::iterator it; for(it=get_dict_ptr.begin(); it!= get_dict_ptr.end(); it++) { QString key = it.key(); QJsonArray value = it.value().toArray(); std::cout << "Key = " << key.toStdString() << " ValueCount = " << value.count() << std::endl; // 循环输出元素 for(int index=0; index  " << val.toStdString() << std::endl; } } // 迭代寻找需要修改的元素并修改 for(it=get_dict_ptr.begin(); it!= get_dict_ptr.end(); it++) { QString key = it.key(); // 如果找到了指定的Key 则将Value中的列表替换到其中 if(key.toStdString() == "Two") { // 替换整个数组 QJsonArray value = {1,2,3,4,5}; get_dict_ptr[key] = value; break; } else if(key.toStdString() == "One") { // 替换指定数组元素 QJsonArray array = get_dict_ptr[key].toArray(); array.replace(0,"lyshark"); array.replace(1,"lyshark"); array.removeAt(1); // 写回原JSON字符串 get_dict_ptr[key] = array; } } // 赋值给根 root["ObjectInArrayJson"] = get_dict_ptr; // 将对象设置到根 root_document.setObject(root); // 规范模式 QByteArray root_string_indented = root_document.toJson(QJsonDocument::Indented); // 写配置文件 writeonly_string("d:/indented_config.json",root_string_indented); return a.exec(); } 

// 读取JSON文本 // https://www.cnblogs.com/lyshark QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // -------------------------------------------------------------------- // 修改数组中的数组 // -------------------------------------------------------------------- QJsonArray array_value = root.value("ArrayJson").toArray(); int insert_index = 0; // 循环查找IP地址,找到后将其弹出 for(int index=0; index 

// 读取JSON文本 QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 // https://www.cnblogs.com/lyshark bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // -------------------------------------------------------------------- // 修改数组中的对象数值 // -------------------------------------------------------------------- QJsonArray array_value = root.value("ObjectJson").toArray(); for(int index=0; index 

// 读取JSON文本 QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 // https://www.cnblogs.com/lyshark bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); // -------------------------------------------------------------------- // 修改对象中的数组元素 // -------------------------------------------------------------------- QJsonArray array_value = root.value("ObjectArrayJson").toArray(); for(int index=0; index 

// 读取JSON文本 QString readonly_string(QString file_path) { // https://www.cnblogs.com/lyshark QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 // https://www.cnblogs.com/lyshark QJsonObject root = root_document.object(); int insert_index = 0; // -------------------------------------------------------------------- // 修改对象中嵌套对象嵌套对象 // -------------------------------------------------------------------- // 寻找节点中数组位置 QJsonArray array_object = root.find("NestingObjectJson").value().toArray(); std::cout << "节点数量: " << array_object.count() << std::endl; for(int index=0; index 

// 读取JSON文本 QString readonly_string(QString file_path) { QFile this_file_ptr(file_path); if(false == this_file_ptr.exists()) { return "None"; } // https://www.cnblogs.com/lyshark if(false == this_file_ptr.open(QIODevice::ReadOnly | QIODevice::Text)) { return "None"; } QString string_value = this_file_ptr.readAll(); this_file_ptr.close(); return string_value; } // 写出JSON到文件 bool writeonly_string(QString file_path, QString file_data) { QFile this_file_ptr(file_path); if(false == this_file_ptr.open(QIODevice::WriteOnly | QIODevice::Text)) { return false; } QByteArray write_byte = file_data.toUtf8(); this_file_ptr.write(write_byte,write_byte.length()); this_file_ptr.close(); return true; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // 读文件 QString readonly_config = readonly_string("d:/config.json"); // 开始解析 解析成功返回QJsonDocument对象否则返回null QJsonParseError err_rpt; QJsonDocument root_document = QJsonDocument::fromJson(readonly_config.toUtf8(), &err_rpt); if (err_rpt.error != QJsonParseError::NoError && !root_document.isNull()) { return 0; } // 获取根节点 QJsonObject root = root_document.object(); int insert_index = 0; // -------------------------------------------------------------------- // 修改对象中嵌套双层数组 // -------------------------------------------------------------------- // 寻找节点中数组位置 QJsonArray array_object = root.find("ArrayNestingArrayJson").value().toArray(); std::cout << "节点数量: " << array_object.count() << std::endl; for(int index=0; index