1.绘制时针

xx.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTimer>
#include<QPainter>
#include <QTime>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

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

    void paintEvent(QPaintEvent *event) override;
private:
    Ui::Widget *ui;

    QTimer *timer;


private slots:
    void updateClock();


};
#endif // WIDGET_H

xxx.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
     ui->setupUi(this);
     timer = new QTimer(this);
     connect(timer, &QTimer::timeout, this, &Widget::updateClock);
     timer->start(1000); // 每秒更新一次
}

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

void Widget::paintEvent(QPaintEvent *event)
{

       QTime time = QTime::currentTime();//获取当前时间
       int hour = time.hour();
       int minute = time.minute();
       int second = time.second();

       QPainter painter(this); // 实例化对象
       painter.setRenderHint(QPainter::Antialiasing); //设置渲染，消除锯齿装


       // 设置时钟中心
       int side = qMin(width(), height());
       painter.translate(width() / 2, height() / 2);//将坐标移到中心
       painter.scale(side / 200, side / 200); //根据窗口，设置绘制的比例

       // 绘制时针
       painter.save();
       painter.rotate(30.0 * ((hour + minute / 60.0)));//绘制时针的旋转
       painter.setPen(Qt::NoPen);
       painter.setBrush(Qt::black);
       painter.drawRect(-5, -50, 10, 50);

       painter.restore();

       // 绘制分针
       painter.save();
       painter.rotate(6.0 * (minute + second / 60.0));
       painter.setPen(Qt::NoPen);
       painter.setBrush(Qt::darkGray);
       painter.drawRect(-3, -70, 6, 70);

       painter.restore();

       // 绘制秒针
       painter.save();
       painter.rotate(6.0 * second);
       painter.setPen(Qt::NoPen);
       painter.setBrush(Qt::red);
       painter.drawRect(-2, -90, 4, 90);


       painter.restore();

       // 绘制时钟刻度
       painter.setPen(Qt::black);
           for (int i = 0; i < 12; ++i) {
               painter.drawLine(88, 0, 96, 0);
               painter.rotate(30.0);
           }

           // 绘制小刻度
           painter.setPen(Qt::gray);
           for (int i = 0; i < 60; ++i) {
               if (i % 5 != 0) { // 跳过大刻度的位置
                   painter.drawLine(92, 0, 96, 0);
               }
               painter.rotate(6.0);
           }
}

void Widget::updateClock()
{
    update();
}

2. 闹钟播报

xxx.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include<QMessageBox>
#include<QTime>
#include<QTimer>
#include <QTextToSpeech>
#include <QDebug>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

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

private slots:

    void timeout_slot1();
    void timeout_slot2();

    void on_startButton_clicked();

    void on_closeButton_clicked();

private:
    Ui::Widget *ui;

    QTimer *timer1;
    QTimer *timer2;
    QTextToSpeech *speecher;
};
#endif // WIDGET_H

xxx.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    speecher = new QTextToSpeech(this);
    timer1 = new QTimer(this);
    timer2 = new QTimer(this);
    timer1->start(1000);
    connect(timer1, &QTimer::timeout, this, &Widget::timeout_slot1);
    connect(timer2, &QTimer::timeout, this, &Widget::timeout_slot2);



}

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

void Widget::timeout_slot1()
{
    QTime  sysTime  = QTime::currentTime();
    QString t = sysTime.toString("hh:mm:ss");
    ui->curtimelab->setText(t);
}
void Widget::timeout_slot2()
{
    if(ui->curtimelab->text()==ui->settimeEdit->text())
    {
        qDebug()<<"时间到";
        QString msg ="现在是北京时间"+ui->settimeEdit->text()+ui->textEdit->toPlainText();

        speecher->say(msg);

        timer2->stop();
        ui->startButton->setDisabled(false);
        ui->textEdit->setDisabled(false);
    }
}

void Widget::on_startButton_clicked()
{
    timer2->start(1000);
    ui->startButton->setDisabled(true);
    ui->textEdit->setDisabled(true);

}

void Widget::on_closeButton_clicked()
{
    timer2->stop();
    ui->startButton->setDisabled(false);
    ui->textEdit->setDisabled(false);

}