Java awt Panel 不会从线程重新绘制，只会在我调整窗口大小时更新

Question

I'm trying to add Labels to a awt panel from a thread, and I'm calling repaint from the thread, but the panel isn't updating, and only updates when I resize the window. I tried many solutions, but none are working, so please help.

public class Updater extends Thread{
    private Panel p;
    public Updater(Panel p) {
        this.p = p;
    }
    public void run() {
        while (true) {
            p.add(new Label("Text"), BorderLayout.NORTH);
            p.repaint();
            System.out.println("Dodao");
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
                
            }
        }
    }
}

public class Main extends Frame {    
    public Panel p;
    private void populateWindow() {      
        p = new Panel();
        p.setLayout(new GridLayout(0, 1));
        add(p);
    }
    public Main() {
        setSize(1000, 500);
        setResizable(true);
        setTitle("Test");   
        populateWindow();
        addWindowListener(new WindowAdapter () {
            public void windowClosing(WindowEvent e) {
                dispose();
            }
        });     
        setVisible(true);
    }
    public static void main(String[] args) {
        Main m = new Main();
        Updater u = new Updater(m.p);
        u.start();
    }
}

Answer 1

Use revalidate() instead of repaint() . Revalidate() is used for components, repaint() is not.