在 Java 中画几秒钟的图像

Question

How can I draw an image that would be available for just a few seconds?

@Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
if (dots % 3 == 0 && dots != 3){
                g.drawImage(clocks, clocksX, clocksY, this);
            }
}

Thanks

Answer 1

Painting of a component is done by setting properties of the component.

So if you want to control whether an image is or isn't painted you would need an instance variable in your class that does the custom painting, lets say drawImage . Then you would need a method to change the state of the variable:

public void setDrawImage(boolean drawImage)
{
    this.drawImage = drawImage;
    repaint();
}

So know your paintComponent() method would look like:

@Override
protected void paintComponent(Graphics g)
{
    super.paintComponent(g);

    if (drawImage)
        g.drawImage(clocks, ...);
}

So now if you want animation you would uses a Swing Timer. So the code would be something like:

Timer timer = new Timer(3000, (e) -> 
{
    yourComponent.setDrawImage(false);
    
    Timer timer2 = (Timer)e.getSource();
    timer2.stop();
};

yourComponent.setDrawImage(true);
timer.start();   

Read the section from the Swing tutorial onHow to Use Swing Timers for more information.

Answer 2

Thank you.

private int t = 0;
        if (dots % 3 == 0 && dots != 3){
            if(t < 2400){
                g.drawImage(clocks, clocksX, clocksY, null);
            }
            Timer timer1 = new Timer(3000, new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    t += 110;

                    if (t >= 10000) {
                        ((Timer)e.getSource()).stop();
                        t = 100000;
                    }
                    repaint();
                }
            });
            System.out.println(t); //its for to test my timer1
            timer1.start();
             if (t >= 30000){
                 timer1.stop();
                 t = 0;
             }
        }

And its work. But when t > 30000, its actually dont stop. And timer2, not working as it should. Maybe because, in this class, where I want to execute this method, there is already another timer? Maybe because of this?

Answer 3

I myself answered my question)) If I already had a timer, I use it. Here is what I wrote and it works:

if (dots % 3 == 0 && dots != 3) {
            t += 300; 
            if (t < 5100) {
                g.drawImage(clocks, clocksX, clocksY, null);
            }
        }

        if (dots % 3 != 0) {
            t = 0;
        }