我最近才开始学习如何使用 swing,并且一直在学习我在网上找到的教程。我基本上按照教程“逐字逐句”进行操作,但出现错误:
ScoreBoard 不是抽象的,不会覆盖 ActionListener 中的抽象方法 actionPerformed(ActionEvent)
所以我的问题是,如果类不是抽象的,我如何在我的类(记分板)中实现 ActionListener?
这是整个代码:(因为我不知道问题出在哪里)
package scoreboard;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class ScoreBoard implements ActionListener{
//Class Variables
int redScore = 0;
int blueScore = 0;
//Class Objects
JPanel titlePanel, scorePanel, buttonPanel;
JLabel redLabel, blueLabel, redLabelT, blueLabelT;
JButton redButton, blueButton, resetButton;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run(){
createFrame();
}
});
}//End Method
public static void createFrame(){
JFrame frame = new JFrame("ScoreBoard");
JFrame.setDefaultLookAndFeelDecorated(true);
ScoreBoard panel = new ScoreBoard();
frame.setContentPane(panel.contentPane());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setSize(250, 190);
frame.setVisible(true);
}//End Method
public JPanel contentPane(){
JPanel basePanel = new JPanel();
basePanel.setLayout(null);
basePanel.setBackground(Color.black);
//Title
titlePanel = new JPanel();
titlePanel.setLayout(null);
titlePanel.setOpaque(false);
titlePanel.setLocation(10, 0);
titlePanel.setSize(250, 30);
basePanel.add(titlePanel);
redLabelT = new JLabel("Red Team");
redLabelT.setLocation(0, 0);
redLabelT.setSize(100, 30);
redLabelT.setForeground(Color.red);
redLabelT.setHorizontalAlignment(0);
titlePanel.add(redLabelT);
blueLabelT = new JLabel("Blue Team");
blueLabelT.setLocation(120, 0);
blueLabelT.setSize(100, 30);
blueLabelT.setForeground(Color.blue);
blueLabelT.setHorizontalAlignment(0);
titlePanel.add(blueLabelT);
//Score
scorePanel = new JPanel();
scorePanel.setLayout(null);
scorePanel.setOpaque(false);
scorePanel.setLocation(10, 40);
scorePanel.setSize(250, 30);
basePanel.add(scorePanel);
redLabel = new JLabel("" + redScore);
redLabel.setLocation(0, 0);
redLabel.setSize(100, 30);
redLabel.setForeground(Color.white);
redLabel.setHorizontalAlignment(0);
scorePanel.add(redLabel);
blueLabel = new JLabel("" + blueScore);
blueLabel.setLocation(120, 0);
blueLabel.setSize(100, 30);
blueLabel.setForeground(Color.white);
blueLabel.setHorizontalAlignment(0);
scorePanel.add(blueLabel);
//Buttons
buttonPanel = new JPanel();
buttonPanel.setLayout(null);
buttonPanel.setOpaque(false);
buttonPanel.setLocation(10, 80);
buttonPanel.setSize(250, 70);
basePanel.add(buttonPanel);
redButton = new JButton("Red Score");
redButton.setLocation(0, 0);
redButton.setSize(100, 30);
redButton.addActionListener(this);
buttonPanel.add(redButton);
blueButton = new JButton("Blue Score");
blueButton.setLocation(120, 0);
blueButton.setSize(100, 30);
blueButton.addActionListener(this);
buttonPanel.add(blueButton);
resetButton = new JButton("Reset");
resetButton.setLocation(0, 40);
resetButton.setSize(220, 30);
resetButton.addActionListener(this);
buttonPanel.add(resetButton);
return basePanel;
}//End Method
public void actions(ActionEvent e){
if(e.getSource() == redButton){
redScore ++;
redLabel.setText("" + redScore);
}else if(e.getSource() == blueButton){
blueScore++;
blueLabel.setText("" + blueScore);
}else if(e.getSource() == resetButton){
redScore = 0;
blueScore = 0;
redLabel.setText("" + redScore);
blueLabel.setText("" + blueScore);
}
}//End Method
}//End Class
此外,如果您可以解释抽象类是什么,那也会有所帮助,但实际上我只需要知道如何让 JButtons 现在工作......
谢谢!