QT学习_QTimer使用

Posted 2021-06-28 Leslie X徐

QT例子

日期和定时器

日期类：

• QTime
• QDate
• QDateTime

时间组件：

• QTimeEdit
• QDateEdit
• QDateTimeEdit
• QCalendarWidget

定时器类

• QTimer
  属性：setInterval()
  信号：timeout()

获取当前日期时间按钮：

void Widget::on_btn_GetTime_clicked()
{
    //get current time
    QDateTime curDateTime = QDateTime::currentDateTime();

    ui->timeEdit->setTime(curDateTime.time());
    ui->dateEdit->setDate(curDateTime.date());
    ui->dateTimeEdit->setDateTime(curDateTime);

    ui->editTime->setText(curDateTime.toString("hh:mm:ss"));
    ui->editDate->setText(curDateTime.toString("yyyy-MM-dd"));
    ui->editDateTime->setText(curDateTime.toString("yyyy-MM-dd hh:mm:ss"));

}

string转时间：

void Widget::on_btnSetDateTime_clicked()
{
    //string->QDataTime
    QString str = ui->editDateTime->text();
    str = str.trimmed();
    if(!str.isEmpty())
    {
        QDateTime datetime = QDateTime::fromString(str,"yyyy-MM-dd hh:mm:ss");
        ui->dateTimeEdit->setDateTime(datetime);
    }
}

日历组件选择日期：

void Widget::on_calendarWidget_selectionChanged()
{
    QDate dt = ui->calendarWidget->selectedDate();
    QString str = dt.toString("yyyy/M/d");
    ui->editCalendar->setText(str);
}

定时器设置：

//构造函数中初始化
 fTimer = new QTimer(this);
    fTimer->stop();
    fTimer->setInterval(1000);
    connect(fTimer,SIGNAL(timeout()),
            this,SLOT(on_timer_timeout()));
           
//设置信号函数
void Widget::on_timer_timeout()
{
    QTime curTime = QTime::currentTime();
    ui->lcdhour->display(curTime.hour());
    ui->lcdmin->display(curTime.minute());
    ui->lcdsec->display(curTime.second());
    int va = ui->progressBar->value();
    va++;
    if(va>100)va=0;
    ui->progressBar->setValue(va);

}

//按键设置时间间隔
void Widget::on_btnSetPeriod_clicked()
{
    int period = ui->spinPeriod->value();
    fTimer->setInterval(period);
}

//设置开始和结束按键
void Widget::on_btnStart_clicked()
{
    fTimer->start();
    fTimeCounter.start();
    ui->btnStart->setEnabled(false);
    ui->btnStop->setEnabled(true);
    ui->btnSetPeriod->setEnabled(false);
}

void Widget::on_btnStop_clicked()
{
    fTimer->stop();
    int tmMsec = fTimeCounter.elapsed();
    int ms = tmMsec%1000;
    int sec = tmMsec/1000;

    QString str;
    str.sprintf("%ds %dms",sec,ms);

    ui->LabElapsTime->setText(str);
    ui->btnStart->setEnabled(true);
    ui->btnStop->setEnabled(false);
    ui->btnSetPeriod->setEnabled(true);
}

结束按键：

void Widget::on_btnExit_clicked()
{
    QApplication* app;
    app->exit();
}

总体code

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

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    fTimer = new QTimer(this);
    fTimer->stop();
    fTimer->setInterval(1000);
    connect(fTimer,SIGNAL(timeout()),
            this,SLOT(on_timer_timeout()));
}

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

void Widget::on_btn_GetTime_clicked()
{
    //get current time
    QDateTime curDateTime = QDateTime::currentDateTime();

    ui->timeEdit->setTime(curDateTime.time());
    ui->dateEdit->setDate(curDateTime.date());
    ui->dateTimeEdit->setDateTime(curDateTime);

    ui->editTime->setText(curDateTime.toString("hh:mm:ss"));
    ui->editDate->setText(curDateTime.toString("yyyy-MM-dd"));
    ui->editDateTime->setText(curDateTime.toString("yyyy-MM-dd hh:mm:ss"));

}

void Widget::on_btnSetDateTime_clicked()
{
    //string->QDataTime
    QString str = ui->editDateTime->text();
    str = str.trimmed();
    if(!str.isEmpty())
    {
        QDateTime datetime = QDateTime::fromString(str,"yyyy-MM-dd hh:mm:ss");
        ui->dateTimeEdit->setDateTime(datetime);
    }
}

void Widget::on_btnSetTime_clicked()
{
    QString str = ui->editTime->text();
    str = str.trimmed();
    if(!str.isEmpty())
    {
        QTime time = QTime::fromString(str,"hh:mm:ss");
        ui->timeEdit->setTime(time);
    }
}

void Widget::on_calendarWidget_selectionChanged()
{
    QDate dt = ui->calendarWidget->selectedDate();
    QString str = dt.toString("yyyy/M/d");
    ui->editCalendar->setText(str);
}

void Widget::on_timer_timeout()
{
    QTime curTime = QTime::currentTime();
    ui->lcdhour->display(curTime.hour());
    ui->lcdmin->display(curTime.minute());
    ui->lcdsec->display(curTime.second());
    int va = ui->progressBar->value();
    va++;
    if(va>100)va=0;
    ui->progressBar->setValue(va);

}


void Widget::on_btnSetPeriod_clicked()
{
    int period = 1000*ui->spinPeriod->value();
    fTimer->setInterval(period);
}

void Widget::on_btnStart_clicked()
{
    fTimer->start();
    fTimeCounter.start();
    ui->btnStart->setEnabled(false);
    ui->btnStop->setEnabled(true);
    ui->btnSetPeriod->setEnabled(false);
}

void Widget::on_btnStop_clicked()
{
    fTimer->stop();
    int tmMsec = fTimeCounter.elapsed();
    int ms = tmMsec%1000;
    int sec = tmMsec/1000;

    QString str;
    str.sprintf("%ds %dms",sec,ms);

    ui->LabElapsTime->setText(str);
    ui->btnStart->setEnabled(true);
    ui->btnStop->setEnabled(false);
    ui->btnSetPeriod->setEnabled(true);
}

void Widget::on_btnExit_clicked()
{
    QApplication* app;
    app->exit();
}

头文件

#ifndef WIDGET_H
#define WIDGET_H

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

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

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

private slots:
    void on_btn_GetTime_clicked();

    void on_btnSetDateTime_clicked();

    void on_btnSetTime_clicked();

    void on_calendarWidget_selectionChanged();

    void on_timer_timeout();

    void on_btnSetPeriod_clicked();

    void on_btnStart_clicked();

    void on_btnStop_clicked();

    void on_btnExit_clicked();

private:
    Ui::Widget *ui;

    QTimer *fTimer;
    QTime fTimeCounter;
};

#endif // WIDGET_H