java - Swing components not displaying

Question

I've had this problem many times before while using Java swing. I run the program, and nothing at all displays but the window; the moment you resize it even by a pixel, everything appears perfectly. Could anyone please tell me why this is happening?
Thanks.

Answer 1

总是从头开始invokeLater()，使用布局管理器，最后pack()制作框架。setVisible()

EventQueue.invokeLater(new Runnable() {

    @Override
    public void run() {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel(new GridLayout(0, 1));
        panel.add(...);
        panel.add(...);
        f.add(new JScrollPane(panel));
        f.pack();
        f.setVisible(true);
    }
});

Answer 2

确保以下代码将出现在 GUI 代码的末尾。

frame.setSize(500,500); // size of the frame

frame.setVisible(true); // make frame window visible