关于Swing 滚动容器包装 JTextPane的有关问题 往高手解答

import java.awt.Color;public class Demo02 {    public static void main(String[] args) {        Icon icon = new ImageIcon("d:Demo\\素材\\阿狸壁纸.jpg");        Font font = new Font("宋体", Font.BOLD, 20);        final JFrame jf = new JFrame("写着玩的记事本");        jf.addWindowListener(new WindowAdapter() {            @Override            public void windowActivated(WindowEvent arg0) {                System.out.println("打开了窗口");            }            @Override            public void windowClosing(WindowEvent e) {                System.out.println("关闭了窗口");            }            @Override            public void windowDeactivated(WindowEvent e) {                System.out.println("最小化了窗口");            }            @Override            public void windowDeiconified(WindowEvent e) {                System.out.println("最大化了窗口");            }        });        final JTextPane textPane = new JTextPane();// 设置输入栏        textPane.setBounds(0, 24, 632, 422);        textPane.setOpaque(false); // 设置控件背景为透明        // jf.getContentPane().add(textPane);        textPane.setCaretColor(new Color(12, 253, 100));        textPane.setSelectedTextColor(Color.BLACK);        textPane.setForeground(Color.WHITE);// 设置文字颜色        textPane.setFont(font);        textPane.setLayout(null);        JMenuBar menuBar = new JMenuBar();        menuBar.setBounds(0, 0, 792, 27);        jf.getContentPane().add(menuBar);        JMenu menu = new JMenu("文件");        menuBar.add(menu);        // jf.getContentPane().add(lblNewLabel);        final JMenuItem mntmNewMenuItem_2 = new JMenuItem("新建");        mntmNewMenuItem_2.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                if (e.getSource() == mntmNewMenuItem_2) {                    System.out.println("选择了新建_快捷键为CTRL+N");                    // textPane.setText("选择了新建_快捷键为CTRL+N");                }            }        });        mntmNewMenuItem_2.setMnemonic('N');        mntmNewMenuItem_2.setAccelerator(KeyStroke.getKeyStroke('N',// 取得快捷键                java.awt.Event.CTRL_MASK));        menu.add(mntmNewMenuItem_2);        final JMenuItem mntmNewMenuItem_1 = new JMenuItem("打开");        mntmNewMenuItem_1.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                if (e.getSource() == mntmNewMenuItem_1) {                    System.out.println("选择了打开_快捷键为CTRL+O");                    // textPane.setText("选择了打开_快捷键为CTRL+O");                }            }        });        mntmNewMenuItem_1.setMnemonic('S');        mntmNewMenuItem_1.setAccelerator(KeyStroke.getKeyStroke('O',// 取得快捷键                java.awt.Event.CTRL_MASK));        menu.add(mntmNewMenuItem_2);        menu.add(mntmNewMenuItem_1);        final JMenuItem mntmNewMenuItem = new JMenuItem("保存");        mntmNewMenuItem.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                if (e.getSource() == mntmNewMenuItem) {                    System.out.println("选择了保存_快捷键为CTRL+S");                    // textPane.setText("选择了保存_快捷键为CTRL+S");                }            }        });        mntmNewMenuItem.setMnemonic('S');        mntmNewMenuItem.setAccelerator(KeyStroke.getKeyStroke('S',// 取得快捷键                java.awt.Event.CTRL_MASK));        menu.add(mntmNewMenuItem_2);        menu.add(mntmNewMenuItem);        final JMenuItem menuItem = new JMenuItem("另存为");        menuItem.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                if (e.getSource() == menuItem) {                    System.out.println("选择了另存为快捷键为CTRL+Z");                    // textPane.setText("选择了另存为_快捷键为CTRL+Z");                }            }        });        menuItem.setMnemonic('Z');        menuItem.setAccelerator(KeyStroke.getKeyStroke('Z',// 取得快捷键                java.awt.Event.CTRL_MASK));        menu.add(mntmNewMenuItem_2);        menu.add(menuItem);        JMenu mnNewMenu = new JMenu("编辑");        menuBar.add(mnNewMenu);        JMenu menu_1 = new JMenu("格式");        menuBar.add(menu_1);        JMenu menu_2 = new JMenu("查看");        menuBar.add(menu_2);        JMenu menu_3 = new JMenu("帮助");        menuBar.add(menu_3);        // jf.add(lblNewLabel);        JPanel jp1 = new JPanel();        JLabel lblNewLabel = new JLabel(icon);// 设置背景        lblNewLabel.setBounds(-11, 24, 643, 422);        jp1.add(textPane);        JScrollPane scrollPane = new JScrollPane(jp1,//设置滚动条                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,                JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);        jf.getContentPane().add(scrollPane);        jf.setLayout(null);//设置JPrame 布局为空 否则会覆盖之前的        jf.setSize(640, 480);        jf.setLocation(300, 400);        jf.setVisible(true);        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 关闭资源    }}