Qt +QTimer 定时器的使用

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

#include <QTimer> //  定时器对象

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private slots:
    void on_buttonStart_clicked();

    void on_buttonStop_clicked();

private:
    Ui::Widget *ui;

    QTimer *myTimer;// 定时器对象
};

#endif // WIDGET_H

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

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

    myTimer = new QTimer(this);

    connect(myTimer,&QTimer::timeout,[=](){

        static int i = 0;
        i++;
        ui->lcdNumber->display(i);
    });
}

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

//按钮Start，转到槽
void Widget::on_buttonStart_clicked()
{
    //启动定时器
    //时间间隔为100ms
    //每隔100ms，定时器myTimer自动触发timeout()
    //如果定时器没有激活，才启动,防止多次点击start按钮出现错误
    if (myTimer->isActive() == false)
    {
       myTimer->start(100);
    }

}

void Widget::on_buttonStop_clicked()
{

    if(myTimer->isActive() == true)
    {
        myTimer->stop();
    }

}