如何在Java中重置JProgressBar？

Question

I have a button and when i click it, then it will start the progressbar . After finishing one time, i want the progressbar to reset and if i click on the button again then it will start fresh.
Here's my code:

else if (action == detectButton) {

            // pb.setVisible(true);

            SwingUtilities.invokeLater(new Runnable() {

                @Override
                public void run() {
                    pb.setValue(0);
                    pb.repaint();
                }
            });

            for (int i = 1; i <= 10; i++) {
                final int val = i;
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        pb.setValue(val);
                        pb.repaint();
                        try {
                            java.lang.Thread.sleep(100);
                        } catch (InterruptedException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }

                });

            }

Now the problem is that when i first run it runs ok but in second attempt it is not resetting the progressbar to 0. How to do it actually??

EDIT: I am repainting the progressbar everytime but i saw that it is not smooth enough to show that 10% happened then 20%..

Answer 1

Your JProgressbar doesn't reset, because it will be repaint after the first Runnable finished. But your java.lang.Thread.sleep(2000); prevent this.

Answer 2

Here is a full example, how to use the progressbar:

public class TestWindow
{

    private JFrame frame;

    /**
     * Launch the application.
     */
    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                try
                {
                    TestWindow window = new TestWindow();
                    window.frame.setVisible(true);
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public TestWindow()
    {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize()
    {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        final JProgressBar progressBar = new JProgressBar();
        progressBar.setBounds(10, 11, 414, 14);
        frame.getContentPane().add(progressBar);

        JButton btnNewButton = new JButton("Reset");
        btnNewButton.setBounds(10, 228, 89, 23);
        frame.getContentPane().add(btnNewButton);

        JButton button = new JButton("Run");
        button.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                Runnable update = new Runnable()
                {

                    @Override
                    public void run()
                    {
                        for (int i = 1; i <= 100; i++)
                        {
                            final int val = i;

                            SwingUtilities.invokeLater(new Runnable()
                            {
                                public void run()
                                {
                                    progressBar.setValue(val);
                                    progressBar.repaint();
                                }

                            });

                            try
                            {
                                java.lang.Thread.sleep(100);
                            }
                            catch (InterruptedException e1)
                            {
                                // TODO Auto-generated catch block
                                e1.printStackTrace();
                            }
                        }
                    }
                };
                Thread t = new Thread(update);
                t.start();
            }
        });

        button.setBounds(109, 228, 89, 23);
        frame.getContentPane().add(button);

        btnNewButton.addActionListener(new ActionListener()
        {

            @Override
            public void actionPerformed(ActionEvent e)
            {
                SwingUtilities.invokeLater(new Runnable()
                {

                    @Override
                    public void run()
                    {
                        progressBar.setValue(0);
                        progressBar.repaint();
                    }
                });
            }
        });

    }
}