JLabel 上的翻转由网格布局中的图像组成？

Question

我有一个带有网格布局的代码和两个 JLabel 图像。我不想每次滚动每张图片时都出现一些文字。当图像不是 JLabel 时，我很熟悉如何执行此操作，但在整个网络上进行了搜索以找到如何在它是未命名的 JLabel 时执行此操作。我不想拥有的两张图片，带有单独的翻转消息是：

ImageIcon(getClass().getResource("giraffe.png"));
            Icon windows = new ImageIcon(getClass().getResource("windows.png"));

这是我的代码：

    public class giraffe implements ActionListener{


        public void actionPerformed(ActionEvent event) {


            JOptionPane.showMessageDialog(null,
                    "Press ok, and see the amazing giraffe outside a window!");

            JDialog giraffewindow = new JDialog();
            Icon giraffe = new ImageIcon(getClass().getResource("giraffe.png"));
            Icon windows = new ImageIcon(getClass().getResource("windows.png"));

            giraffewindow.setLayout(new GridLayout(1, 2, 0, 0));
            giraffewindow.add(new JLabel (windows));
            giraffewindow.add(new JLabel (giraffe));


            giraffewindow.pack();
            giraffewindow.setTitle("GIRAFFE!");
            giraffewindow.setVisible(true);
            giraffewindow.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

            /*
             * I want to have a rollover on EACH IMAGE so that when they rollover the image you see different text.
             */

        }

非常感谢您抽出宝贵时间阅读本文，我非常感谢您为帮助其他程序员所做的努力！

Answer 1

先看看 How to Write a Mouse Listener。

基本上，您想为每个标签附加一个 MouseListener 并监视 mouseEntered 和 mouseExited 事件，根据您的要求更新标签状态

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            try {
                JLabel left = new JLabel(new ImageIcon(ImageIO.read(...))));
                left.setVerticalTextPosition(JLabel.BOTTOM);
                left.setHorizontalTextPosition(JLabel.CENTER);
                left.setHorizontalAlignment(JLabel.CENTER);
                left.setVerticalAlignment(JLabel.CENTER);
                left.setText(" ");
                JLabel right = new JLabel(new ImageIcon(ImageIO.read(...))));
                right.setVerticalTextPosition(JLabel.BOTTOM);
                right.setHorizontalTextPosition(JLabel.CENTER);
                right.setHorizontalAlignment(JLabel.CENTER);
                right.setVerticalAlignment(JLabel.CENTER);
                right.setText(" ");

                setLayout(new GridLayout(1, 2));

                add(left);
                add(right);

                left.addMouseListener(new MouseAdapter() {
                    @Override
                    public void mouseEntered(MouseEvent e) {
                        left.setText("I'm on the left");
                    }

                    @Override
                    public void mouseExited(MouseEvent e) {
                        left.setText(" ");
                    }
                });
                right.addMouseListener(new MouseAdapter() {
                    @Override
                    public void mouseEntered(MouseEvent e) {
                        right.setText("I'm on the right");
                    }

                    @Override
                    public void mouseExited(MouseEvent e) {
                        right.setText(" ");
                    }
                });
            } catch (IOException exp) {
                exp.printStackTrace();
            }
        }

    }

}

您可能还想看看 Reading/Loading an Image

Answer 2

您还可以通过执行以下操作来创建通用侦听器：

ImageIcon giraffe = new ImageIcon(...);
giraffe.setDescription("Giraffe Description");

然后你的听众可能看起来像：

MouseListener ml = new MouseAdapter()
{
    @Override
    public void mouseEntered(MouseEvent e)
    {
        JLabel label = (JLabel)e.getSource();
        ImageIcon icon = (ImageIcon)label;
        label.setText( icon.getDescription() );
    }

    @Override
    public void mouseExited(MouseEvent e)
    {
        JLabel label = (JLabel)e.getSource();
        label.setText(" ");
    }
}

然后将侦听器添加到标签：

JLabel giraffeLabel = new JLabel( giraffe );
giraffe.addMouseListener( ml );

同一侦听器可用于您的其他 JLabel，因为事件代码知道组件生成了事件。

JLabel 上的翻转由网格布局中的图像组成？

Rollover on JLabel which consists of image within grid layout?

java

swing

jlabel