关于QT定时器和消息对话框的实例训练

结果：

源文件：

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

    Widget::Widget(QWidget *parent)
        : QWidget(parent)
        , ui(new Ui::Widget)
        ,speecher(new QTextToSpeech(this))
    {
        ui->setupUi(this);

        timerid1=startTimer(1000);//系统时间定时器
    }

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

    void Widget:: timerEvent(QTimerEvent *e){//重写定时器事件函数
        if(e->timerId()==timerid1){
            //获取系统时间
            QTime sys_time =QTime::currentTime();

            ui->sys_time_label->setText(sys_time.toString(" 提瓦特大陆实时\n HH:mm:ss\n"));//显示时间

            ui->sys_time_label->setAlignment(Qt::AlignCenter);//显示居中

            int count=1;
            if(sys_time.toString("HH:mm:ss")==txt){//判断系统时间和闹钟时间是否一致
                while(count<=5){//播报5次
                speecher->say(ui->speak_label_3->text());
                count++;
                }
            }
        }
    }

    void Widget::on_pushButton_clicked()
    {
        txt=ui->alarm_clock_lineEdit->text();//获取闹钟时间
        if(txt==""){
            QMessageBox::information(NULL,"title","请输入有效时间",QMessageBox::Ok);//防止闹钟时间格式出错
        }else {
            if(ui->pushButton->text()=="启动"){

                //修改按钮为关闭
                ui->pushButton ->setText("关闭");
            }else {
                speecher->stop();//关闭按钮中断播报
                //修改按钮为启动
                ui->pushButton->setText("启动");

            }
    }
    }

头文件：

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTimerEvent>//定时器事件类
#include <QTime>//时间类
#include <QMessageBox>//消息对话框
#include <QTextToSpeech>//语音播报

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT
    int timerid1;//系统时间定时器
    QString txt;
public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void timerEvent(QTimerEvent *e);//重写定时器事件函数


private slots:
    void on_pushButton_clicked();

private:
    Ui::Widget *ui;
    QTextToSpeech *speecher;
};
#endif // WIDGET_H

登录界面窗口代码（续上篇）

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

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);

    //去除头部
    this->setWindowFlag(Qt::FramelessWindowHint);

    //去除空白部分
    this->setAttribute(Qt::WA_TranslucentBackground);

    ui->Username_lineEdit->setClearButtonEnabled(1);//全部删除键
    ui->Password_lineEdit_2->setClearButtonEnabled(1);
}

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


void Widget::on_pushButton_2_clicked()//exit按钮
{
    QMessageBox msg(QMessageBox::Warning,"Title","是否确定退出登录？",QMessageBox::Yes|QMessageBox::No,NULL);
    int ret=msg.exec();
    if(ret==QMessageBox::Yes){
        this->close();
    }else if(ret==QMessageBox::No){
        msg.close();
    }
}

void Widget::on_pushButton_clicked()//login按钮
{
    if(ui->Username_lineEdit->text()=="路明非"&&ui->Password_lineEdit_2->text()=="sakura"){
        QMessageBox::information(NULL, "Title", "login success!", QMessageBox::Ok);//登录成功弹窗
        emit jump_signal();
        this->close();
    }else{
        int ret=QMessageBox::critical(NULL, "Title", "login failed.\n""Pleasa input username/passward again.\n""Y/N?", QMessageBox::Yes | QMessageBox::No);//登录失败弹窗
        if(ret==QMessageBox::Yes){
        ui->Password_lineEdit_2->home(true);
        ui->Password_lineEdit_2->del();
        }else if(ret==QMessageBox::No){
            this->close();
        }
    }
}

void Widget::on_Password_lineEdit_2_returnPressed()
{
    if(ui->Username_lineEdit->text()=="路明非"&&ui->Password_lineEdit_2->text()=="sakura"){
        QMessageBox::information(NULL, "Title", "login success!", QMessageBox::Ok);//登录成功弹窗
        emit jump_signal();
        this->close();
    }else{
        int ret=QMessageBox::critical(NULL, "Title", "login failed.\n""Pleasa input username/passward again.\n""Y/N?", QMessageBox::Yes | QMessageBox::No);//登录失败弹窗
        if(ret==QMessageBox::Yes){
        ui->Password_lineEdit_2->home(true);
        ui->Password_lineEdit_2->del();
        }else if(ret==QMessageBox::No){
            this->close();
        }
    }
}




void Widget::on_pushButton_3_clicked()//叉按钮
{
    this->close();
}

void Widget::on_pushButton_4_clicked()//最小化按钮
{
    this->showMinimized();
}