qt+vs利用QTimer创建倒计时报错

Question

qt+vs利用QTimer创建倒计时报错

.h

#pragma once

#include <QtWidgets/QMainWindow>
#include "ui_QtWidgetsApplication2.h"
#include"qtimer.h"

class QtWidgetsApplication2 : public QMainWindow
{
    Q_OBJECT

public:
    QtWidgetsApplication2(QWidget *parent = nullptr);
    ~QtWidgetsApplication2();
    QTimer *timer;

private:
    Ui::QtWidgetsApplication2Class ui;
private slots:
    void a();
};

.cpp

#include "QtWidgetsApplication2.h"

QtWidgetsApplication2::QtWidgetsApplication2(QWidget *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);
    QTimer *timer = new QTimer();
    connect(timer, &QTimer::timeout, this, &QtWidgetsApplication2::a);
    timer->start(1000);
}

QtWidgetsApplication2::~QtWidgetsApplication2()
{}

void QtWidgetsApplication2::a()
{
    for (int i = 100; i > 0; i--)
    {
        this->ui.label->setText(QString::number(i));
    }
    timer->stop();

}

运行可以显示出窗口，并明显感觉到延迟了1s，说明问题出现在timeout后，但是并没有找到具体哪里有问题

Answer 1

把构造函数里的

QTimer *timer = new QTimer();

改成

timer = new QTimer();