java - 如何将不同的监听器绑定(bind)到不同的ScrollPane

Question

我有一个类，它定义了带有两个 JList 的图形界面。对于每个 JList，我想关联一个方法 public void valueChanged(ListSelectionEvent s) 但我不能这样做(显然)。那么我该如何修复它呢？

这是我的代码:

public class Inbox implements ListSelectionListener {

    public static void main(String[] args) {
        Inbox inbox = new Inbox();
    }

    JFrame frame = new JFrame();
    JPanel panel = new JPanel();
    JPanel titlePanel = new JPanel();
    JPanel centerPanel = new JPanel();
    JPanel listPanel = new JPanel();
    JPanel listRicPanel = new JPanel();
    JPanel listInvPanel = new JPanel();
    JPanel messPanel = new JPanel();
    JPanel buttonPanel = new JPanel();

    GridBagConstraints c;
    JButton indietro = new JButton("Indietro");
    JButton ok = new JButton("Ok");

    String ricevuti[] = {"1", "2", "3", "4", "5", "6", "7", "8", "9"};
    JList ricList = new JList(ricevuti);

    String inviati[] = {"A", "B", "C", "D", "E"};
    JList invList = new JList(inviati);

    Inbox() {
        frame.setTitle("Inbox"); //nome della finestra (frame)
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel);
       frame.setVisible(true);

        panel.setLayout(new BorderLayout());
        centerPanel.setLayout(new BorderLayout());
        listPanel.setLayout(new GridLayout(2, 0));

        panel.add(titlePanel, BorderLayout.NORTH);
        panel.add(buttonPanel, BorderLayout.SOUTH);
        panel.add(centerPanel, BorderLayout.CENTER);
        buttonPanel.add(indietro);
        buttonPanel.add(ok);

        centerPanel.add(listPanel, BorderLayout.WEST);
        centerPanel.add(messPanel, BorderLayout.CENTER);

        listPanel.add(listRicPanel);
        listPanel.add(listInvPanel);

        /** ScrollPane containing the first list **/
        ricList.setVisibleRowCount(10);
        ricList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        listRicPanel.add(new JScrollPane(ricList));
        ricList.addListSelectionListener(this);

        /** ScrollPane containing the second list **/
        invList.setVisibleRowCount(10);
        invList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        listInvPanel.add(new JScrollPane(invList));
        invList.addListSelectionListener(this);


        frame.pack();

    }


    /**
     * First listener.
     */
    public void valueChanged(ListSelectionEvent e) {
        String str = (String) ricList.getSelectedValue();
        if(str.equals("Alex"))
            System.out.println("Alex");
        else if(str.equals("John"))
            System.out.println("John");
        else
            System.out.println("Other name");
    }

    /**
     * Second listener.
     */
    public void valueChanged(ListSelectionEvent e) {
        String str = (String) invList.getSelectedValue();
        if(str.equals("Alex"))
            System.out.println("Alex");
        else if(str.equals("John"))
            System.out.println("John");
        else
            System.out.println("Other name");
    }

}

我希望程序能够将不同的监听器组合到不同的 scroolPane，就像我这样做的那样？

非常感谢!

Answer 1

它必须是一种方法，但您可以使用 e.getSource() 方法来获取触发事件的 JList 实例。然后就可以像这样使用了

public void valueChanged(ListSelectionEvent e) {
    String str = (String) ((JList)e.getSource()).getSelectedValue();
    if(str.equals("Alex"))
        System.out.println("Alex");
    else if(str.equals("John"))
        System.out.println("John");
    else
        System.out.println("Other name");
}

当然，监听器必须添加到两个列表实例