Java 用于 JPanel 的 addMouseListener

addMouseListener for a JPanel

提问by user2360545

Today I have a problem.. My program make a 8x8 grid and show the coord when I click on a JButton.

今天我遇到了一个问题..我的程序制作了一个 8x8 的网格并在我点击JButton.

BUT I refuse to use JButtonand I need to go for JPanel.. But my addMouseListenerisn't working so I don't know how is it possible to fix that I'm searching since 4h.....

但是我拒绝使用JButton，我需要去JPanel......但我addMouseListener没有工作所以我不知道如何解决我从 4 小时开始搜索的问题.....

    package coordboutons;

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

    public class CoordBoutons extends JFrame {

        CoordBoutons() {
            super("GridLayout");
            setDefaultCloseOperation(EXIT_ON_CLOSE);
            Container contenant = getContentPane();
            contenant.setLayout(new GridLayout(8, 8));

            for (int i = 0; i < 8; i++) 
                for (int j = 0; j < 8; j++)
                    contenant.add(new CaseEchiquier(i, j));

            pack();
            setVisible(true);
        }

        **class CaseEchiquier extends JPanel** {
            private int lin, col;
            CaseEchiquier(int i, int j) {
                lin = i;
                col = j;
                setPreferredSize(new Dimension(80, 75));
                setBackground((i + j) % 2 == 0 ? Color.WHITE : Color.GRAY);
                addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent evt) {
                        System.out.println((char)('a' + col) + "" + (8 - lin));

                    }
                });
            }


        }

        public static void main(String[] args) {
            JFrame.setDefaultLookAndFeelDecorated(true);
            CoordBoutons coordBoutons = new CoordBoutons();
        }
    }

采纳答案by MadProgrammer

JPaneldoesn't have ActionListenercapabilities. Instead, you need to use a MouseListener

JPanel没有ActionListener能力。相反，您需要使用MouseListener

import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class CoordBoutons extends JFrame {

    CoordBoutons() {
        super("GridLayout");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        Container contenant = getContentPane();
        contenant.setLayout(new GridLayout(8, 8));

        for (int i = 0; i < 8; i++) {
            for (int j = 0; j < 8; j++) {
                contenant.add(new CaseEchiquier(i, j));
            }
        }

        pack();
        setVisible(true);
    }

    class CaseEchiquier extends JPanel {

        private int lin, col;

        CaseEchiquier(int i, int j) {
            lin = i;
            col = j;
            setPreferredSize(new Dimension(80, 75));
            setBackground((i + j) % 2 == 0 ? Color.WHITE : Color.GRAY);
            addMouseListener(new MouseAdapter() {
                private Color background;

                @Override
                public void mousePressed(MouseEvent e) {
                    background = getBackground();
                    setBackground(Color.RED);
                    repaint();
                }

                @Override
                public void mouseReleased(MouseEvent e) {
                    setBackground(background);
                }
            });
//            addActionListener(new ActionListener() {
//                public void actionPerformed(ActionEvent evt) {
//                    System.out.println((char) ('a' + col) + "" + (8 - lin));
//
//                }
//            });
        }
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame.setDefaultLookAndFeelDecorated(true);
                CoordBoutons coordBoutons = new CoordBoutons();
            }
        });
    }
}

Take a look at How to Write Mouse Listenersfor more details...

查看如何编写鼠标侦听器以获取更多详细信息...

回答by Marlon Bernardes

The problem is that the method addActionListenerdoes not exists for a JPanel. You should use the appropriate listener for this case (java.awt.event.MouseListener). Since MouseListeneris an interface (and you don't want to implement all of its methods), you could use a MouseAdapterand override only the method(s) you need, like this:

问题是addActionListenerJPanel 不存在该方法。对于这种情况，您应该使用适当的侦听器 ( java.awt.event.MouseListener)。由于MouseListener是一个接口（并且您不想实现其所有方法），您可以使用 aMouseAdapter并仅覆盖您需要的方法，如下所示：

addMouseListener(new MouseAdapter() {
    @Override
    public void mouseClicked(MouseEvent e) {
        System.out.println((char)('a' + col) + "" + (8 - lin));
    }
});