Question

我创建了2个JLists'addGroupList'和'addApkList'。我正在使用model.addElement（arrayList1.get（arrayList1.size（） - 1））向addGroupList添加元素;问题是，我想根据addGroupList的选定值更新addApkList。为此，我正在尝试添加事件监听器，以便在选择列表项但事件不会触发时我可以采取行动。我该怎么做才能做到这一点？以下是我正在使用的代码。

    model1 = new DefaultListModel();
    model2 = new DefaultListModel();

    addApkList = new JList(model1);
    addGroupList = new JList(model2);

    scrollPane1 = new JScrollPane();
    scrollPane1.setViewportView(addApkList);
    scrollPane2 = new JScrollPane();
    scrollPane2.setViewportView(addGroupList);

这样我就定义了JList。以下方式我添加了addGroupList

的元素

model1.addElement(arrayList1.get(arrayList1.size()-1));

以下面的方式我添加了听众。

addGroupList.addListSelectionListener(new ListSelectionListener() {

        @Override
        public void valueChanged(ListSelectionEvent lse) {
            if (!lse.getValueIsAdjusting()) {
              System.out.println("Selection trigerred");
            }
        }
    });

此代码似乎没有任何变化。我做错了什么？我也试过了

model1.addListDataListener(new ListDataListener() {

            @Override
            public void intervalAdded(ListDataEvent lde) {
                System.out.println("ddddddddddd");
                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            }

            @Override
            public void intervalRemoved(ListDataEvent lde) {
                System.out.println("ddddddddddd");
                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            }

            @Override
            public void contentsChanged(ListDataEvent lde) {
                System.out.println("ddddddddddd");
                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            }
        });

Answer 1

以下方式我添加了addGroupList
的元素
model1.addElement(arrayList1.get(arrayList1.size()-1));

不，你没有。 model1是addApkList而不是addGroupList的列表模型：

 addApkList = new JList(model1);

应为model2.addElement(arrayList1.get(arrayList1.size()-1))。

在任何情况下，我怀疑当你只是简单地将一个项目添加到列表模型时，你期望被ListSelectionEvent被解雇。这不会发生。您需要将添加的项目设置为所选项目：

Object item = arrayList1.get(arrayList1.size()-1);
model2.addElement(item);
addGroupList.setSelectedValue(item, true);

请查看JList.setSelectedValue(Object anObject, boolean shouldScroll)了解更多详情。

Answer 2

我创建了2个JLists'addGroupList'和'addApkList'。我补充说使用addGroupList的元素 model.addElement（arrayList1.get（arrayList1.size（） - 1））;事情是，我想要根据addGroupList的选定值更新addApkList。对于这个，我正在尝试添加事件监听器，以便我可以采取行动选择列表项但事件不是trigerring时的东西。我该怎么做才能做到这一点？以下是我正在使用的代码。

例如

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class Testing extends JFrame {

    private static final long serialVersionUID = 1L;
    private DefaultListModel listModel = new DefaultListModel();
    private DefaultListModel listModelEmpty = new DefaultListModel();
    private JList list = new JList(listModel);
    private JList listEmpty = new JList(listModelEmpty);
    private JPanel panel = new JPanel(new GridLayout(1, 1));
    private int currentSelectedRow = 0;
    private int xX = 0;

    public Testing() {
        setLocation(400, 300);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        for (int x = 0; x < 9; x++) {
            listModel.addElement("" + x);
            xX++;
        }
        JScrollPane sp = new JScrollPane(list);
        list.addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent lse) {
                if (!lse.getValueIsAdjusting()) {
                    System.out.println("Selection trigerred");
                }
            }
        });
        JScrollPane spEmpty = new JScrollPane(listEmpty);
        panel.add(spEmpty);
        panel.add(sp);
        add(panel, BorderLayout.CENTER);
        JButton btn1 = new JButton("Reset Model CastingModel");
        add(btn1, BorderLayout.NORTH);
        btn1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                //list.clearSelection();
                DefaultListModel model = (DefaultListModel) list.getModel();
                model.removeAllElements();
                for (int x = 0; x < 9; x++) {
                    model.addElement("" + (x + xX));
                    xX++;
                }
                list.setModel(model);
            }
        });

        JButton btn2 = new JButton("Reset Model directly from Model");
        add(btn2, BorderLayout.SOUTH);
        btn2.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                //list.clearSelection();
                listModel.removeAllElements();
                for (int x = 0; x < 9; x++) {
                    listModel.addElement("" + (x + xX));
                    xX++;
                }
            }
        });
        pack();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Testing().setVisible(true);
            }
        });
    }
}

如何将侦听器事件添加到由DefaultListModel对象添加的JList元素？

2 个答案: