做了一个自制的小闹钟，能够自己输入时间，以及对应的闹铃，时间到了自动播放设定的闹铃，可以随时取消重新设定，采用分文件编译

        注意：需要在.pro文件中加入：QT       += core gui texttospeech

代码如下：

wideget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QKeyEvent>     //键盘事件类
#include <QMouseEvent>   //鼠标事件类
#include <QIcon>
#include <QPushButton>
#include <QLabel>
#include <QLineEdit>
#include <QMovie>
#include <QObject>
#include <QMessageBox>
#include <QTimer>            //定时器类
#include <QTime>             //时间类
#include <QTimerEvent>       //定时器事件类
#include <QDateTime>         //日期时间类
#include <QTextToSpeech>


QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

signals:


public slots:
    void start_slots();
    void timeout_slots();     //自定义处理超时信号的槽函数
    void cancel_slots();     //自定义取消按钮槽函数

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

    void mouseMoveEvent(QMouseEvent *event);       //鼠标移动事件
    void mousePressEvent(QMouseEvent *event);      //鼠标点击事件

    void speakText(const QString &text);

private:
    Ui::Widget *ui;
    QPoint temp;                //移动窗口中间辅助向量
    QLabel *system_time,*lab1;         //显示系统时间
    QLineEdit *mod_time,*clock_txt;             //可编辑的时间、闹钟输出的文字
    QPushButton *start_button,*cancel_button;   //启动按钮和取消按钮

    int tid = 0;       //定时器id号
    QTimer t1;        //定义一个定时器变量


};
#endif // WIDGET_H

main.cpp

#include "widget.h"

#include <QApplication>

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

 widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QDebug>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->setFixedSize(500,500);                    //设置页面初始尺寸大小
    this->setWindowFlag(Qt::FramelessWindowHint);   //将头部隐藏

    //标签类
    system_time = new QLabel(this);          //系统时间
    system_time->resize(200,140);
    system_time->move(50,50);
    system_time->setScaledContents(true);
    system_time->setStyleSheet("background-color:pink; border-radius:20;\
                                font-size:20px;font-weight:bold");
    system_time->setWindowOpacity(0.1);

    //按钮类
    start_button = new QPushButton("启动",this);
    cancel_button = new QPushButton("取消",this);

    //设置位置
    start_button->move(system_time->x()+system_time->width()+15,110);
    cancel_button->move(start_button->x()+start_button->width()+5,start_button->y());
    //设置大小
    start_button->resize(90,80);
    cancel_button->resize(90,80);
   // start_button->setStyleSheet("border-radius:20");

    //行标签类
    mod_time = new QLineEdit(this);
    mod_time->move(system_time->y()+system_time->width()+15,system_time->y());
    mod_time->setPlaceholderText("输入定时");
    mod_time->resize(180,30);

    clock_txt = new QLineEdit(this);
    clock_txt->move(50,230);
    clock_txt->resize(400,250);
    clock_txt->setPlaceholderText("输入闹铃");

    // 设置文本对齐到左上角
    clock_txt->setAlignment(Qt::AlignLeft | Qt::AlignTop);
    clock_txt->setStyleSheet("QLineEdit { padding-left: 0px; }");

    //连接信号与槽，按下按钮开始执行功能
    connect(start_button, &QPushButton::clicked, this, &Widget::start_slots);
    connect(&t1, &QTimer::timeout, this, &Widget::timeout_slots);
    connect(cancel_button, &QPushButton::clicked, this, &Widget::cancel_slots);
}

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

//鼠标移动事件
void Widget::mouseMoveEvent(QMouseEvent *event)
{
    this->move(event->globalPos() - temp);
}

//鼠标点击事件
void Widget::mousePressEvent(QMouseEvent *event)
{
    temp = event->globalPos() - this->pos();    //求出中间辅助变量
    if(event->button() == Qt::RightButton)
    {
        this->close();
    }
}


void Widget::start_slots()
{
    t1.start(1000);          //每隔指定时间，发送一个timeout信号
}

void Widget::timeout_slots()
{
    //获取系统时间
    QTime sysTime = QTime::currentTime();
    //将QTime类对象转变成字符串
    QString sysTimeStr = sysTime.toString("hh:mm:ss");
    this->system_time->setText(sysTimeStr);
    system_time->setAlignment(Qt::AlignCenter);

    //将3个地方设置成不可点击
    start_button->setEnabled(false);
    mod_time->setReadOnly(true);
    clock_txt->setReadOnly(true);

    //比较逻辑，如果和我输入的时间相等，就发出声音
    QString modTimeStr = mod_time->text();
    if(sysTimeStr == modTimeStr)
    {
        qDebug()<<"发出声音";
        speakText(clock_txt->text());
    }
}

void Widget::cancel_slots()
{
    int res = QMessageBox::information(this,
                                       "提示",
                                       "真的要取消么",
                                       QMessageBox::Yes|QMessageBox::No,
                                       QMessageBox::Yes);
    if(res == QMessageBox::Yes)
    {
        qDebug()<<"解除限制功能";
        t1.stop();
        start_button->setEnabled(true);
        mod_time->setReadOnly(false);
        clock_txt->setReadOnly(false);

    }
    else if(res == QMessageBox::No)
    {
        qDebug()<<"继续执行程序";
    }
}

void Widget::speakText(const QString &text)
{
    QTextToSpeech *speaker = new QTextToSpeech;
    speaker->say(text);
}

输出结果如下：