JAVA GUI学习

public class JTabbedPaneKnow extends JFrame
{
    JTabbedPane jTabbedPane;
    JPanel jPanelRed;
    JPanel jPanelGreen;
    JPanel jPanelYellow;
    JPanel jPanelBlue;
    public JTabbedPaneKnow()
    {
        init();
        this.setBounds(200, 50, 500, 500);
        this.setTitle("选项卡 - 知识");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        this.add(jTabbedPane);
    }
    public void init()
    {
        jPanelBlue = new JPanel();jPanelBlue.setBackground(Color.blue);jPanelBlue.setName("蓝色卡牌");
        jPanelGreen = new JPanel();jPanelGreen.setBackground(Color.green);jPanelGreen.setName("绿色卡牌");
        jPanelRed = new JPanel();jPanelRed.setBackground(Color.red);jPanelRed.setName("红色卡牌");
        jPanelYellow = new JPanel();jPanelYellow.setBackground(Color.yellow);jPanelYellow.setName("黄色卡牌");
        
        //第一个参数：选项卡的标题所在位置：上下左右
        //第二个参数：即选项卡呈现的方式：当窗口变小时：卡标题向下排列，或不重排列出现滚动条
        jTabbedPane = new JTabbedPane(JTabbedPane.TOP,JTabbedPane.SCROLL_TAB_LAYOUT);
        
        //第一个参数：即选项卡显示的标题
        //第二个参数：即选项卡没张卡对应的面板
        jTabbedPane.add("蓝色卡牌", jPanelBlue);jTabbedPane.add("绿色卡牌", jPanelGreen);
        jTabbedPane.add("红色卡牌", jPanelRed);jTabbedPane.add("黄色卡牌", jPanelYellow);
        
        //设置默认的选项卡页，方式一：通过选项卡的索引
        jTabbedPane.setSelectedIndex(1);
        
        //设置默认的选项卡页，方式二：通过选项卡变量名
        jTabbedPane.setSelectedComponent(jPanelGreen);
        
        //获取当前卡页的选项卡索引
        int index = jTabbedPane.getSelectedIndex();
        //获取当前卡页的选项卡面板
        JPanel jPanel = (JPanel) jTabbedPane.getSelectedComponent();
        System.out.println(jPanel.getName());
        
        //为选项卡添加监听器
        jTabbedPane.addChangeListener(new JTabbedPaneChangeListener());
    }
    private class JTabbedPaneChangeListener implements ChangeListener
    {
        @Override
        public void stateChanged(ChangeEvent e)
        {
            JTabbedPane jTabbedPane = (JTabbedPane) e.getSource();
            JOptionPane.showMessageDialog(null, ((JPanel)jTabbedPane.getSelectedComponent()).getName()+"：被打开了");
        }
    }
    public static void main(String[] args)
    {
        JTabbedPaneKnow jTabbedPaneKnow = new JTabbedPaneKnow();
        jTabbedPaneKnow.setVisible(true);
    }

}