QPropertyAnimation不动画

Question

This is my code:

void Widget::update()
{
    if (a==1)
    {
        QPushButton button("Animated Button");
        button.show();

        QPropertyAnimation *animation =
                    new QPropertyAnimation(&button, "geometry");
        animation->setDuration(10000);
        animation->setStartValue(QRect(0, 0, 100, 30));
        animation->setEndValue(QRect(250, 250, 100, 30));

        animation->start();
        a++;
    }
}

void Widget::on_pushButton_clicked()
{
    a=1;
}

I am newbie in C++, how can I make this work?

Answer 1

I suggest you read a good C++ book, or at the very least go though http://www.cplusplus.com/doc/tutorial/ .

For starters, you probably meant to call update() after a==1 in on_pushButton_clicked()? There is also a problem with your push button going out of scope at the end of the function, so you need to do

QPushButton *button = new QPushButton("Animated Button", this); 

Finally, update() is a virtual function in QWidget (which I assume Widget derives?). Why are you overriding it? You probably want to call it something like startAnimatinon() instead.