如何使用鼠标侦听器调用另一个类？答案

【问题标题】：How do I use a mouse listener to call another class?如何使用鼠标侦听器调用另一个类？
【发布时间】：2016-08-26 15:38:02
【问题描述】：

我有一些鼠标监听器的点点滴滴，但我不知道如何将它们联系在一起。当用户单击“玩游戏”按钮时，我正在尝试激活井字游戏。协助将不胜感激。

    import java.awt.*;
    import java.awt.BorderLayout;
    import java.awt.FlowLayout;
    import java.awt.EventQueue;
    import javax.swing.UIManager;
    import javax.swing.UnsupportedLookAndFeelException;
    import java.awt.GridBagLayout;
    import java.awt.event.*;
    import java.awt.event.ActionListener.*;
    import javax.swing.*;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.JLabel;
    import javax.swing.JButton;
    import javax.swing.ImageIcon;
    import javax.swing.border.EmptyBorder;
    import javax.swing.JOptionPane;
    import java.awt.Color;

    public class Use_PF_Interface extends JFrame implements Pet_Fish_Interface, MouseListener
     {
        // instance variables - replace the example below with your own
        private JFrame window;
        private JPanel backgroundPanel;
        private JLabel lblBackgroundImage = new JLabel();
        private JButton feedButton = new JButton("Feed Fish");
        private JButton playGamesButton = new JButton("Play Game");
        volatile private boolean mouseDown = false;

        //creates frame window
        public Use_PF_Interface()
        {
           setTitle("Virtual Pet Fish");
           setSize(400, 400);

           //initializes panels and panel layout
           backgroundPanel = new JPanel(); 
           backgroundPanel.setOpaque(false); 
           backgroundPanel.setLayout(new FlowLayout());

           lblBackgroundImage.setLayout(new FlowLayout());

           //sets background image of panel
           lblBackgroundImage.setIcon(new ImageIcon("OCEAN2.jpg"));
           lblBackgroundImage.setLayout(new BorderLayout()); 
           lblBackgroundImage.setBounds(0, 0, 400, 400);


            //adds button to panels
            backgroundPanel.add(feedButton);
            backgroundPanel.add(playGamesButton);
            lblBackgroundImage.add(backgroundPanel);


            add(lblBackgroundImage);


            feedButton.addMouseListener(this);
            playGamesButton.addMouseListener(listener);

            addMouseListener(this);


            }//creates frame window

         /**
         * This method will create an action for the button.
         * @pre none
         * @return tic tac toe game
         * @param none
         * @post none
         */

         public void mousePressed(MouseEvent e)
         {

             if (e.getButton() ==  MouseEvent.playGamesButton)
             {
               mouseDown = true;
               Tic_Tac_Toe();
              }
        }

        public void mouseReleased(MouseEvent e)
        {
             if(e.getButton() == MouseEvent.feedButton)
             {
                mouseDown = false;

             }
         }

          public void mouseExited(MouseEvent e)
          {
          }

我目前收到此错误：Use_PF_interface 不是抽象的，并且不会覆盖 java.awt.event.MouseListener 中的抽象方法 mouseEntered(java.awt.event.MouseEvent)

【问题讨论】：

标签： java mouselistener

【解决方案1】：

不太确定这是否是问题所在，但该类中是否应该有一个 mouseEntered 方法可以如前所述覆盖？

【讨论】：

【解决方案2】：

解决方案非常简单。 MouseListener 是一个接口。接口是具有方法的类，实现该接口的类必须包含这些方法。即使这些方法不包含任何内容，您也必须将它们包含在您的代码中。所以如果你想实现 MouseListener 你必须重写这 5 个方法：

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;


public class Example implements MouseListener {

@Override
public void mouseClicked(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mousePressed(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mouseReleased(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mouseEntered(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mouseExited(MouseEvent e) {
    // TODO Auto-generated method stub

}


}

顺便说一句，你不能只使用一个 ActionListener 吗，你想做什么？

【讨论】：