Qt天气预报1——JSon与网络读取

最新推荐文章于 2025-09-24 11:04:04 发布

原创最新推荐文章于 2025-09-24 11:04:04 发布 · 160 阅读

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CC 4.0 BY-SA版权

文章标签：

#qt #json #开发语言

本文介绍了如何在C++中使用QJsonObject解析JSON文件以及通过QNetworkAccessManager从网络获取数据，并递归处理嵌套结构。

下面是这一天代码，我们可以分成两部分。

1.JSON文件打印

在下面代码中，我们首先要先获取Json文件的key，key一定为QString类型。

void fromjson(QJsonObject obj){
    QStringList keys= obj.keys();
    for(int i=0;i<keys.size();i++){
        QString key=keys[i];
        QJsonValue value=obj.value(key);
        if(value.isBool()){
           qDebug()<<key<<":"<<value.toBool();
        }
        else if(value.isString()){
           qDebug()<<key<<":"<<value.toString();
        }
        else if(value.isDouble()){
           qDebug()<<key<<":"<<value.toInt();
        }
        else if(value.isObject()){
            fromjson(value.toObject());
        }
        else if (value.isArray()) {
            QJsonArray array = value.toArray();
            for (int i = 0; i < array.size(); i++) {
                QJsonValue arrayValue = array[i];
                if (arrayValue.isObject()) {
                    fromjson(arrayValue.toObject());
                } else if (arrayValue.isBool()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toBool();
                } else if (arrayValue.isString()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toString();
                } else if (arrayValue.isDouble()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toDouble();
                }
            }
        }
    }
}

2.网络信息读取

可以认为是固定格式：



1.创建服务： QNetworkAccessManager mnetworkaccessmange
2.创建相应：QNetworkRequest request;
3.创建URL：QUrl url("http://t.weather.sojson.com/api/weather/city/"+citycode);
4.利用URL访问网站： request.setUrl(url);
5.创建回应： QNetworkReply *reply=mnetworkaccessmange.get(request);
6.创建循环读入结束： QObject::connect(reply,&QNetworkReply::finished,&loop, &QEventLoop::quit);

void readnetwork(QString citycode){
     QNetworkAccessManager mnetworkaccessmange;
     QNetworkRequest request;
     QUrl url("http://t.weather.sojson.com/api/weather/city/"+citycode);
     request.setUrl(url);
     QNetworkReply *reply=mnetworkaccessmange.get(request);
     QEventLoop loop;
     QObject::connect(reply,&QNetworkReply::finished,&loop, &QEventLoop::quit);
     loop.exec();
     if(reply->error()==QNetworkReply::NoError){
         QByteArray Data = reply->readAll();
         QJsonDocument Data_Json=QJsonDocument::fromJson(Data);
         if(!Data_Json.isObject()){
             qDebug()<<"Not an object!";
                     return;
         }
         QJsonObject obj = Data_Json.object();
         fromjson(obj);
     }
     reply->deleteLater();
}

#include "mainwindow.h"
#include"QDebug"
#include <QApplication>
#include <QCoreApplication>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include<QString>
void fromjson(QJsonObject obj){
    QStringList keys= obj.keys();
    for(int i=0;i<keys.size();i++){
        QString key=keys[i];
        QJsonValue value=obj.value(key);
        if(value.isBool()){
           qDebug()<<key<<":"<<value.toBool();
        }
        else if(value.isString()){
           qDebug()<<key<<":"<<value.toString();
        }
        else if(value.isDouble()){
           qDebug()<<key<<":"<<value.toInt();
        }
        else if(value.isObject()){
            fromjson(value.toObject());
        }
        else if (value.isArray()) {
            QJsonArray array = value.toArray();
            for (int i = 0; i < array.size(); i++) {
                QJsonValue arrayValue = array[i];
                if (arrayValue.isObject()) {
                    fromjson(arrayValue.toObject());
                } else if (arrayValue.isBool()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toBool();
                } else if (arrayValue.isString()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toString();
                } else if (arrayValue.isDouble()) {
                    qDebug() << key << "[" << i << "]:" << arrayValue.toDouble();
                }
            }
        }
    }
}
void readnetwork(QString citycode){
     QNetworkAccessManager mnetworkaccessmange;
     QNetworkRequest request;
     QUrl url("http://t.weather.sojson.com/api/weather/city/"+citycode);
     request.setUrl(url);
     QNetworkReply *reply=mnetworkaccessmange.get(request);
     QEventLoop loop;
     QObject::connect(reply,&QNetworkReply::finished,&loop, &QEventLoop::quit);
     loop.exec();
     if(reply->error()==QNetworkReply::NoError){
         QByteArray Data = reply->readAll();
         QJsonDocument Data_Json=QJsonDocument::fromJson(Data);
         if(!Data_Json.isObject()){
             qDebug()<<"Not an object!";
                     return;
         }
         QJsonObject obj = Data_Json.object();
         fromjson(obj);
     }
     reply->deleteLater();
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    readnetwork ("101010100");
    w.show();
    return a.exec();
}