Java：同时运行多个while循环

Question

I'm trying to make several JRadioButtons blink at the same time with this blink method:

private void blink(JRadioButton button, boolean blinking)
{
    if(blinking)
    {
        while(true)
        {   
            try 
            {
                button.setSelected(true);
                Thread.sleep(500);
                button.setSelected(false);
                Thread.sleep(500);
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }
    }
    else
    {
        button.setSelected(false);
    }
}

I know it has something to do with threads but I'm not that familiar with them.

Answer 1

I'm trying to make several JRadioButtons blink at the same time with this blink method

IMHO you don't need multiple while loops.

Just add all buttons you want to blink to an ArrayList , then in the same while loop, loop over that list and blink the buttons. So, instead of

button.setSelected(true);
Thread.sleep(500);
button.setSelected(false);
Thread.sleep(500);

You can use

for(int i=0; i<yourList.size(); i++) {
    yourList.get(i).setSelected(true);
}
Thread.sleep(500);
for(int i=0; i<yourList.size(); i++) {
    yourList.get(i).setSelected(false);
}
Thread.sleep(500);

But this is a bad practice. Use the Timer class and schedule a thread to execute every 500 ms instead:

Timer t = new Timer(500, new ActionListener() {
    boolean selected = false; 

    @Override
    public void actionPerformed(ActionEvent e) {
        selected = !selected;
        for(int i=0; i<yourList.size(); i++) {
            yourList.get(i).setSelected(selected);
        }
    }
});
t.start();

Answer 2

You can't animate the GUI by using Thread.sleep . In fact, you must never call Thread.sleep on the Event Dispatch Thread because that very thread is in charge of repainting the GUI, which it will clearly not be able to do while sleeping.

What you must use is the Swing Timer class and schedule it to repeat at the desired interval.