Qt获取某地的天气情况

weather.pro (其中要加入network模块)

#-------------------------------------------------
#
# Project created by QtCreator 2019-03-30T13:54:31
#
#-------------------------------------------------

QT       += core gui
QT += network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = weather
TEMPLATE = app


SOURCES += main.cpp
        widget.cpp

HEADERS  += widget.h

FORMS    += widget.ui

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private:
    Ui::Widget *ui;
    QNetworkAccessManager *manager;   
    QString fengli;       //风力
    QString wendu;        //温度
    QString weather_type;  //天气类型
private slots:
    void replyFinished(QNetworkReply *);
    void on_pushButton_clicked();
};

#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QUrl>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    manager = new QNetworkAccessManager(this);
    connect(manager, &QNetworkAccessManager::finished, this, &Widget::replyFinished);

}

Widget::~Widget()
{
    delete ui;
}

void Widget::on_pushButton_clicked()
{
    QString address = "http://wthrcdn.etouch.cn/weather_mini?city=";
    QString city = ui->lineEdit->text();
    QString total = address + city;
    const char *url = total.toUtf8().data();

    /**
    qDebug()<<city;
    char url[256] = "http://wthrcdn.etouch.cn/weather_mini?city=";
    char *ch = city.toUtf8().data();
    sprintf(url,"%s%s",url,ch);
    **/
    manager->get(QNetworkRequest(QUrl(url)));
}

void Widget::replyFinished(QNetworkReply *reply)
{
    QString all = reply->readAll();
    ui->textBrowser->setText(all);
    QJsonParseError err;
    QJsonDocument json_recv = QJsonDocument::fromJson(all.toUtf8(),&err);//解析json对象
    qDebug() << err.error;
    if(!json_recv.isNull())
    {
        QJsonObject object = json_recv.object();

        if(object.contains("data"))
        {
            QJsonValue value = object.value("data");  // 获取指定 key 对应的 value
            if(value.isObject())
            {
                QJsonObject object_data = value.toObject();
                if(object_data.contains("forecast"))
                {
                    QJsonValue value = object_data.value("forecast");
                    if(value.isArray())
                    {
                        QJsonObject today_weather = value.toArray().at(0).toObject();
                        weather_type = today_weather.value("type").toString();

                        QString low = today_weather.value("low").toString();
                        QString high = today_weather.value("high").toString();
                        wendu = low.mid(low.length()-3,4) +"~"+ high.mid(high.length()-3,4);
                        QString strength = today_weather.value("fengli").toString();
                        strength.remove(0,8);
                        strength.remove(strength.length()-2,2);
                        fengli = today_weather.value("fengxiang").toString() + strength;
                        ui->type->setText(weather_type); //显示天气类型
                        ui->wendu->setText(wendu);   //显示温度
                        ui->fengli->setText(fengli); //显示风力
                    }
                }
            }
        }

    }else
    {
        qDebug()<<"json_recv is NULL or is not a object !!";
    }
    reply->deleteLater();
}

main.cpp

#include "widget.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();

    return a.exec();
}

图形界面：