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);
  }
  

• 界面