我有使用我的方法的问题＆＃34; changeStyle＆＃34;改变我的JButtons的外观。我做了一个方法，它将改变我的JButton的背景，边框和不透明度。我尝试使用另一种方法来缩短第一个代码，但它返回一个错误，＆＃34;方法changeStyle（）未定义为JButton类型。＆＃34;
我试图缩短的代码：
public void buttonChange(){
rock.setBackground(defaultColor);
rock.setBorder(defaultBorder);
rock.setOpaque(false);
paper.setBackground(defaultColor);
paper.setBorder(defaultBorder);
paper.setOpaque(false);
scissor.setBackground(defaultColor);
scissor.setBorder(defaultBorder);
scissor.setOpaque(false);
switch(main.playerChoice){
case 1:
rock.setBackground(Color.cyan);
rock.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
rock.setOpaque(true);
break;
case 2:
paper.setBackground(Color.cyan);
paper.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
paper.setOpaque(true);
break;
case 3:
scissor.setBackground(Color.cyan);
scissor.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
scissor.setOpaque(true);
break;
default:
rock.setBackground(defaultColor);
rock.setBorder(defaultBorder);
rock.setOpaque(false);
paper.setBackground(defaultColor);
paper.setBorder(defaultBorder);
paper.setOpaque(false);
scissor.setBackground(defaultColor);
scissor.setBorder(defaultBorder);
scissor.setOpaque(false);
break;
}
}
这是我为缩短buttonChange所做的功能：
package RPS;
import java.awt.Color;
import javax.swing.JButton;
import javax.swing.border.Border;
public class changeStyle extends JButton{
public changeStyle(Color color, Border border, Boolean bol){
setBackground(color);
setBorder(border);
setOpaque(bol);
}
}
整个代码：
package RPS;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.ThreadLocalRandom;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.border.Border;
import javax.swing.border.EmptyBorder;
import RPS.changeStyle;
public class main extends JFrame{
private static String version = "V. 0.02";
private JPanel contentPane;
JPanel titlePane = new JPanel();
JLabel title = new JLabel("Rock Paper Scissor " + version);
JSplitPane split1 = new JSplitPane();
JButton exit = new JButton("Exit");
JButton play = new JButton("Play");
JSplitPane split2 = new JSplitPane();
JSplitPane split3 = new JSplitPane();
JSplitPane split4 = new JSplitPane();
JButton rock = new JButton("Rock");
JButton paper = new JButton("Paper");
JButton scissor = new JButton("Scissor");
static int playerChoice;
static int computerChoice;
static int playerScore;
static int computerScore;
static String finalScore;
JLabel plScore = new JLabel("Player Score: " + playerScore);
JLabel compScore = new JLabel("Computer Score: " + computerScore);
JButton reset = new JButton("Reset");
Color defaultColor = new JButton().getBackground();
Border defaultBorder = new JButton().getBorder();
public static void main(String[] args) {
try {
main frame = new main();
frame.setVisible(true);
frame.setResizable(false);
} catch (Exception e) {
e.printStackTrace();
}
}
public main() {
setTitle("Rock Paper Scissor " + version);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
setContentPane(contentPane);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setLayout(new BorderLayout());
add(titlePane, BorderLayout.PAGE_START);
titlePane.add(title);
titlePane.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));
add(split2, BorderLayout.LINE_START);
split2.setOrientation(JSplitPane.VERTICAL_SPLIT);
split2.setEnabled(false);
split2.setTopComponent(plScore);
split2.setBottomComponent(rock);
split2.setDividerLocation(this.getHeight()/4);
split2.setDividerSize(0);
rock.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
main.playerChoice = 1;
//System.out.println(main.playerChoice);
buttonChange();
}
});
plScore.setFont(plScore.getFont().deriveFont(12F));
plScore.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
add(split3, BorderLayout.CENTER);
split3.setOrientation(JSplitPane.VERTICAL_SPLIT);
split3.setEnabled(false);
split3.setTopComponent(compScore);
split3.setBottomComponent(paper);
split3.setDividerLocation(this.getHeight()/4);
split3.setDividerSize(0);
paper.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
main.playerChoice = 2;
//System.out.println(main.playerChoice);
buttonChange();
}
});
compScore.setFont(compScore.getFont().deriveFont(12F));
compScore.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
add(split4, BorderLayout.LINE_END);
split4.setOrientation(JSplitPane.VERTICAL_SPLIT);
split4.setEnabled(false);
split4.setTopComponent(reset);
split4.setBottomComponent(scissor);
split4.setDividerLocation(this.getHeight()/4);
split4.setDividerSize(0);
reset.setSize(25, 75);
scissor.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
main.playerChoice = 3;
//System.out.println(main.playerChoice);
buttonChange();
}
});
reset.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
finalScore = "";
computerChoice = 0;
playerChoice = 0;
playerScore = 0;
computerScore = 0;
plScore.setText("Player Score: " + playerScore);
plScore.setForeground(Color.black);
compScore.setText("Computer Score: " + computerScore);
compScore.setForeground(Color.black);
buttonChange();
}
});
//add(rock, BorderLayout.LINE_START);
split2.setPreferredSize(new Dimension(this.getWidth()/3 -6,0));
//add(paper, BorderLayout.CENTER);
split3.setPreferredSize(new Dimension(this.getWidth()/3 -6,0));
//add(scissor, BorderLayout.LINE_END);
split4.setPreferredSize(new Dimension(this.getWidth()/3 -6,0));
add(split1, BorderLayout.PAGE_END);
split1.setOrientation(JSplitPane.HORIZONTAL_SPLIT);
split1.setEnabled(false);
split1.setDividerLocation(this.getWidth()/2);
split1.setDividerSize(0);
split1.setLeftComponent(play);
split1.setRightComponent(exit);
exit.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
System.exit(0);
}
});
play.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int rand = ThreadLocalRandom.current().nextInt(1, 4);
main.computerChoice = rand;
//System.out.println(main.computerChoice);
plScore.setForeground(Color.black);
compScore.setForeground(Color.black);
if(main.playerChoice == main.computerChoice){
finalScore = "Tie!";
JOptionPane.showMessageDialog(null, finalScore, "Result", JOptionPane.INFORMATION_MESSAGE);
}else if(main.playerChoice == 1){
switch(main.computerChoice){
case 2:
finalScore = "Computer Wins!";
break;
case 3:
finalScore = "Player Wins!";
}
}else if(main.playerChoice == 2){
switch(main.computerChoice){
case 3:
finalScore = "Computer Wins!";
break;
case 1:
finalScore = "Player Wins!";
}
}else if(main.playerChoice == 3){
switch(main.computerChoice){
case 2:
finalScore = "Computer Wins!";
break;
case 1:
finalScore = "Player Wins!";
}
}else{
JOptionPane.showMessageDialog(contentPane, "You didn't choose!!!", "Error", JOptionPane.ERROR_MESSAGE);
}
while(finalScore == "Player Wins!"){
playerScore+=1;
plScore.setText("Player Score: " + playerScore);
//INSERT POP UP
JOptionPane.showMessageDialog(contentPane, finalScore, "Result", JOptionPane.INFORMATION_MESSAGE);
plScore.setForeground(Color.green);
finalScore = "";
}
while(finalScore == "Computer Wins!"){
computerScore+=1;
compScore.setText("Computer Score: " + computerScore);
//INSTERT POP UP
JOptionPane.showMessageDialog(contentPane, finalScore, "Result", JOptionPane.INFORMATION_MESSAGE);
compScore.setForeground(Color.red);
finalScore = "";
}
main.playerChoice = 0;
}
});
}
public void buttonChange(){
rock.setBackground(defaultColor);
rock.setBorder(defaultBorder);
rock.setOpaque(false);
paper.setBackground(defaultColor);
paper.setBorder(defaultBorder);
paper.setOpaque(false);
scissor.setBackground(defaultColor);
scissor.setBorder(defaultBorder);
scissor.setOpaque(false);
switch(main.playerChoice){
case 1:
rock.setBackground(Color.cyan);
rock.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
rock.setOpaque(true);
break;
case 2:
paper.setBackground(Color.cyan);
paper.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
paper.setOpaque(true);
break;
case 3:
scissor.setBackground(Color.cyan);
scissor.setBorder(BorderFactory.createLineBorder(Color.blue, 2, true));
scissor.setOpaque(true);
break;
default:
rock.setBackground(defaultColor);
rock.setBorder(defaultBorder);
rock.setOpaque(false);
paper.setBackground(defaultColor);
paper.setBorder(defaultBorder);
paper.setOpaque(false);
scissor.setBackground(defaultColor);
scissor.setBorder(defaultBorder);
scissor.setOpaque(false);
break;
}
}
}
感谢您的时间。
答案 0 :(得分：1)
扩展类并添加功能以使父类不能使用该功能，只有新类的实例及其子级才能访问它，因此当您使用{{1}时}，JButton rock = new JButton("Rock");将不具有rock的功能（它不是changeStyle的实例，那怎么能呢？）
我们可以进入关于多态和对象转换的语义，但是我们只是说你应该使用
changeStyle现在，您可以调用changeStyle rock = new changeStyle();
方法。注意，如果您希望在创建文本changeStyle时将文本String传递给它，则需要覆盖按钮的构造函数
Java命名约定还会建议类名应该以大写字符开头，因此changeStyle应该是ChangeStyle，虽然它看起来不是什么大问题，但它会使代码更容易为他人阅读，并为您阅读其他人的代码，这只是一个使用的好习惯