JPanel内鼠标移动事件

Question

我在处理鼠标事件时遇到了一些问题。我有一个JPanel放在JLayeredPane里面，而JLayeredPane又被放在JScrollPane里面。虽然我对Swing的操作比较新手，但基本上，我想让JPanel对鼠标移动作出反应，但一直无法实现。

public class CellHighlighter extends JPanel implements MouseMotionListener{

    public CellHighlighter(){

    }

    public void mouseMoved(MouseEvent evt){
        System.out.println(evt.getPoint().x + ", " + evt.getPoint().y);
    }

    public void mouseDragged(MouseEvent evt){System.out.println("message");}

}

任何帮助都将受到非常感激，谢谢您的提前帮助！

- Shane Fitzgerald

Answer 1

你是否将你的JPanel对象注册到MouseListener？就像这样：

    public CellHighlighter(){
       this.addMouseMotionListener(this);
    }

也许你需要将MouseListener添加到ScrollPane或LayeredPane中？

- HectorLector

---

需要强调的是，即使通过addMouseListener已经添加了相同的实例，仍然必须使用addMouseMotionListener。 - O. R. Mapper

Answer 2

以下是一些您可以使用的演示代码:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class ReactPanel extends JPanel implements MouseMotionListener {

    public ReactPanel(){
        setPreferredSize(new Dimension(450, 450));
        setBackground(Color.GREEN);
        addMouseMotionListener(this);
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        System.out.println("Mouse dragged (" + e.getX() + ',' + e.getY() + ')');
    }

    @Override
    public void mouseMoved(MouseEvent e) {
        System.out.println("Mouse moved (" + e.getX() + ',' + e.getY() + ')');

    }

    public static void main(String[] args){
        //Create and set up the window.
        JFrame frame = new JFrame("MouseMotionEventDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new ReactPanel();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }
}

- Allen Z.