QT5笔记： 16. 时间和定时器的常用功能

例子

#ifndef WIDGET_H
#define WIDGET_H

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

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 on_btnGetTime_clicked();

    void on_btnSetTime_clicked();

    void on_btnSetDate_clicked();

    void on_btnSetDateTime_clicked();

    void on_calendarWidget_selectionChanged();
    /**
     * @brief on_timer_timeOut
     * @note 定时器超时的槽函数
     */
    void on_timer_timeOut();

    void on_btnStart_clicked();

    void on_btnStop_clicked();

    void on_btnSetInterval_clicked();

private:
    Ui::Widget *ui;
    /**
     * @brief timer 定时器timer
     */
    QTimer *timer;

    /**
     * @brief timeCounter 计时器
     */
    QTime timeCounter;
};
#endif // WIDGET_H

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

#include <QTimer>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    timer = new QTimer(this);
    timer->stop();
    connect(timer, SIGNAL(timeout()), this, SLOT(on_timer_timeOut()));
}

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

/**
 * @brief Widget::on_btnGetTime_clicked
 * @note 获取本地时间，并显示在文本框中
 */
void Widget::on_btnGetTime_clicked()
{
    QDateTime curDateTime = QDateTime::currentDateTime();
    QString date = curDateTime.toString("yyyy-MM-dd");
    QString time = curDateTime.toString("HH:mm:ss");
    QString dateTime = curDateTime.toString("yyyy-MM-dd HH:mm:ss");
    ui->editDate->setText(date);
    ui->dateEdit->setDate(curDateTime.date());
    ui->editTime->setText(time);
    ui->timeEdit->setTime(curDateTime.time());
    ui->editDateTime->setText(dateTime);
    ui->dateTimeEdit->setDateTime(curDateTime);
}

/**
 * @brief Widget::on_btnSetTime_clicked
 * @note 获取文本框中的内容，然后转换为时间
 */
void Widget::on_btnSetTime_clicked()
{
    QString timeStr = ui->editTime->text();
    QTime time = QTime::fromString(timeStr, "HH:mm:ss");
    ui->timeEdit->setTime(time);
}

/**
 * @brief Widget::on_btnSetDate_clicked
 * @note 获取文本框中的内容，然后转换为日期
 */
void Widget::on_btnSetDate_clicked()
{
    QString dateStr = ui->editDate->text();
    QDate date = QDate::fromString(dateStr, "yyyy-MM-dd");
    ui->dateEdit->setDate(date);
}

/**
 * @brief Widget::on_btnSetDateTime_clicked
 * @note 获取文本框中的内容，然后转换为时间和日期
 */
void Widget::on_btnSetDateTime_clicked()
{
    QString dateTimeStr = ui->editDateTime->text();
    QDateTime dateTime = QDateTime::fromString(dateTimeStr, "yyyy-MM-dd HH:mm:ss");
    ui->dateTimeEdit->setDateTime(dateTime);
}

/**
 * @brief Widget::on_calendarWidget_selectionChanged
 * @note  获取日期控件的所选择的日期，然后设置到文本框
 */
void Widget::on_calendarWidget_selectionChanged()
{
    QDate date = ui->calendarWidget->selectedDate();
    ui->editDateCalendar->setText(date.toString("yyyy-MM-dd"));
}

/**
 * @brief Widget::on_timer_timeOut
 * @note timer的超时事件，QT的timer要手动去定义timer、槽，手动去写connect
 */
void Widget::on_timer_timeOut()
{
    ui->lcdH->display(QTime::currentTime().hour());
    ui->lcdM->display(QTime::currentTime().minute());
    ui->lcdS->display(QTime::currentTime().second());
}

/**
 * @brief Widget::on_btnStart_clicked
 * @note 启动timer，并设置控件是否禁用
 */
void Widget::on_btnStart_clicked()
{
    timer->start();
    timeCounter.start();

    ui->btnStart->setEnabled(false);
    ui->btnSetInterval->setEnabled(false);
    ui->btnStop->setEnabled(true);
}

/**
 * @brief Widget::on_btnStop_clicked
 * @note 停止timer，并设置控件是否禁用
 */
void Widget::on_btnStop_clicked()
{
    timer->stop();
    int time = timeCounter.elapsed();
    int second = time / 1000;
    int miniSec = time % 1000;
    QString str = QString::asprintf("%d\" %d",second, miniSec);
    ui->label_8->setText(str);

    ui->btnStart->setEnabled(true);
    ui->btnSetInterval->setEnabled(true);
    ui->btnStop->setEnabled(false);
}

/**
 * @brief Widget::on_btnSetInterval_clicked
 * @note 设置timer的interval
 */
void Widget::on_btnSetInterval_clicked()
{
    int value = ui->spinBox->value();
    timer->setInterval(value);
}

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