网络接口获取链接：免费节假日API_原百度节假日API

HolidayJudge.h

#pragma once

#include <QtWidgets/QWidget>
#include "ui_HolidayJudge.h"

enum DATESTATE
{
    WORK=0,//工作日
    DAYOFF,//休息日
    HOLIDAY//节假日
};

class HolidayJudge : public QWidget
{
    Q_OBJECT

public:
    HolidayJudge(QWidget *parent = nullptr);
    ~HolidayJudge();

private slots:
    void slotQueryGet();
    void slotQueryPost();

private:
    void init();
    
private:
    Ui::HolidayJudgeClass ui;

    QMap<DATESTATE, QString> m_dateInfoMap;
};

HolidayJudge.cpp

#include "HolidayJudge.h"

#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QList>
#include <QSslError>

HolidayJudge::HolidayJudge(QWidget *parent)
    : QWidget(parent)
{
    ui.setupUi(this);

    init();

    QObject::connect(ui.pushButton_queryGet, &QPushButton::clicked, this, &HolidayJudge::slotQueryGet);
    QObject::connect(ui.pushButton_queryPost, &QPushButton::clicked, this, &HolidayJudge::slotQueryPost);
}

HolidayJudge::~HolidayJudge()
{}

void HolidayJudge::slotQueryGet()
{
    QNetworkAccessManager* manager = new QNetworkAccessManager(this);
    connect(manager, &QNetworkAccessManager::finished,
        this, [=](QNetworkReply* reply) {
            //ui.textBrowser->append(QString(reply->readAll()));
            int val = QString(reply->readAll()).toInt();//0：工作日，1：休息日，2：节假日
            QString info = ui.dateEdit->date().toString("yyyy/MM/dd") + QString("是%1").arg(m_dateInfoMap.value(static_cast<DATESTATE>(val)));
            ui.textBrowser->append("get: " + info);

            reply->deleteLater();
        });

    QString date = ui.dateEdit->date().toString("yyyyMMdd");
    QUrl url("http://tool.bitefu.net/jiari/?d=" + date);
    manager->get(QNetworkRequest(url));

    //开启事件循环，等待直到服务器返回数据后再执行
	//QEventLoop eventLoop;
	//connect(manager, SIGNAL(finished(QNetworkReply*)), &eventLoop, SLOT(quit()));
	//eventLoop.exec();

    manager->deleteLater();
}

void HolidayJudge::slotQueryPost()
{
    QNetworkAccessManager* accessManager = new QNetworkAccessManager(this);
    QNetworkRequest request;
    QString date = ui.dateEdit->date().toString("yyyyMMdd");
    QUrl url("http://tool.bitefu.net/jiari/?d=" + date);
    request.setUrl(url);
    request.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("application/json"));

    QNetworkReply* reply = accessManager->post(request, QByteArray());
    QObject::connect(reply, &QNetworkReply::readyRead, this, [this, reply]() {
        int val = QString(reply->readAll()).toInt();//0：工作日，1：休息日，2：节假日
        QString info = ui.dateEdit->date().toString("yyyy/MM/dd") + QString("是%1").arg(m_dateInfoMap.value(static_cast<DATESTATE>(val)));
        ui.textBrowser->append("post: " + info);
        reply->deleteLater();
        });
    QObject::connect(reply, &QNetworkReply::errorOccurred,
        this, [=](QNetworkReply::NetworkError error) {
        
        });
    QObject::connect(reply, &QNetworkReply::sslErrors,
        this, [=](const QList<QSslError>& error){

    });

}

void HolidayJudge::init()
{
    m_dateInfoMap.insert(WORK, "工作日");
    m_dateInfoMap.insert(DAYOFF, "休息日");
    m_dateInfoMap.insert(HOLIDAY, "节假日");
}

效果展示