JSpinner在动作监听器中不起作用

Question

I have an actionlistener inside another actionlistener when i create my jspinner inside the outer one it works but in the inner one it doesn't. this is my code.what would the problem be?

this is the code which doesn't work and if I put sp and js out of the inner action listener it works.

    menuItem = new JMenuItem("Insert Exams", KeyEvent.VK_E);
    menuItem.addActionListener(new ActionListener() {


        @Override
        public void actionPerformed(ActionEvent arg0) {
            count = 0;
            jt = new ArrayList[3];
            for (int i = 0; i < 3; i++)
                jt[i] = new ArrayList<JTextField>();
            panel = new JPanel();
            panel.setLocation(0, 0);
            panel.setSize(d.width, d.height);
            panel.setLayout(null);

            JButton add = new JButton("add Exam");
            add.setSize(120, 80);
            add.setLocation(250, 100);


            add.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent arg0) {
                    sp = new SpinnerNumberModel(1, 1, 5, 1);
                    js = new JSpinner(sp);
                    js.setSize(100, 30);
                    js.setLocation(450, 80 + count * 50);
                    panel.add(js);

                    for (int i = 1; i < 3; i++) {
                        JTextField jt1 = new JTextField(20);
                        jt1.setSize(150, 30);
                        jt1.setLocation(450 + i * 200, 80 + count * 50);

                        jt[i].add(jt1);
                        panel.add(jt1);
                    }
                    count++;
                    repaint();
                }
            });
            panel.add(add);

            setContentPane(panel);

        }
    });

Answer 1

You should be using revalidate instead of repaint .

You should also be relying on a LayoutManager rather then using setSize and setLocation