我如何编写代码来显示每个 JPanel 中的每个字母，以及如何旋转。 （JFrame、NetBeans）
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【中文标题】我如何编写代码来显示每个 JPanel 中的每个字母，以及如何旋转。 （JFrame、NetBeans）【英文标题】：How do i write a code to display every letter in every JPanel, and how do I rotate. (JFrame, NetBeans) 【发布时间】：2020-10-10 06:25:53 【问题描述】：我是 Java 新手，我在课堂上被分配为以下问题开发代码，我只能做设计，之后我不知道如何继续为每个问题添加操作按钮。
这是问题：
https://www.chegg.com/homework-help/questions-and-answers/write-java-application-creates-frame-similar-one-shown--four-letter-word-shown-four-panels-q52352988
如果有人解决过，请分享。 提前感谢您的帮助！
【问题讨论】：
我很困惑。 JFrame 上唯一的按钮是“旋转”按钮。 【参考方案1】：由于这是家庭作业，我不会提供完整的代码。我会提供sn-ps。
这是我创建的 GUI。我希望我可以将其显示为动画 GIF。
我添加了一个停止按钮来停止单词旋转。
我通过将问题分解为越来越小的步骤来编写代码，然后对每个步骤进行编码。在完成之前，我对 GUI 进行了许多测试。有些测试失败了，我不得不修改代码。
我写了 6 节课。主类创建了JFrame，字母面板组，底部控制面板。我写了一个LetterPanel 类来创建一个字母面板。我写了 3 个actionListener 类，一个用于JComboBox，一个用于旋转按钮，一个用于停止按钮。我写了一个 Animation 类，它每秒旋转字母。
这是我用来获得 4 种绿色的颜色。
Color[] colors = new Color(50, 117, 1),
new Color(65, 159, 0), new Color(88, 201, 5),
new Color(107, 242, 2)
;
设置主要的JPanel 来保存4 个LetterPanel 对象有点棘手。以下是我的做法。
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
LetterPanel 类扩展了 JPanel 并覆盖了 paintComponent 方法。首先，我调用了super.paintComponent 方法。始终首先调用super.paintComponent 方法。然后，我画了背景颜色。然后，我画了这封信。
为了在每个LetterPanel 中绘制字母，我使用了以下代码。
/**
* Draw a String centered in the middle of the panel.
*
* @param g2d The Graphics2D instance.
* @param text The String to draw.
* @param font The Font to draw with.
*/
public void drawCenteredString(Graphics2D g2d,
String text, Font font)
FontMetrics metrics = g2d.getFontMetrics(font);
int x = (getWidth() - metrics.stringWidth(text)) / 2;
int y = ((getHeight() - metrics.getHeight()) / 2) +
metrics.getAscent();
g2d.setFont(font);
g2d.drawString(text, x, y);
JComboBox actionListener 从 JComboBox 中获取选定的单词。 Oracle 教程How to Use Combo Boxes 告诉您我是如何设置单词 JComboBox。
旋转按钮actionListener 检查是否同时检查了JCheckBox 字段。然后它检查是否没有检查JCheckBox 字段。最后，它启动了一个Animation 线程。
停止按钮停止Animation 线程。
Animation 线程旋转单词并暂停 1 秒以让您看到旋转。
这是运行循环。
@Override
public void run()
while (running)
updatePanel();
sleep(1000L);
if (leftSelected)
word = rotateLeft(word);
else
word = rotateRight(word);
这是我的轮换方法。
private String rotateLeft(String word)
return word.substring(1) + word.substring(0, 1);
private String rotateRight(String word)
return word.substring(word.length() - 1) +
word.substring(0, word.length() - 1);
编辑添加；
我忘了我已经回答了这个问题。时间已经过去了，所以我将发布整个应用程序。我将附加类设为内部类，因此我可以将此代码作为一个块发布。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class RotateWord implements Runnable
public static void main(String[] args)
SwingUtilities.invokeLater(new RotateWord());
private Animation animation;
private JCheckBox leftBox;
private JCheckBox rightBox;
private JComboBox<String> wordComboBox;
private JFrame frame;
private LetterPanel[] letterPanel;
private String word;
public RotateWord()
this.word = "WORD";
@Override
public void run()
frame = new JFrame("Rotate Word");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createWordPanel(word), BorderLayout.CENTER);
frame.add(createControlPanel(word),
BorderLayout.AFTER_LAST_LINE);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
private JPanel createWordPanel(String word)
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
Color[] colors = new Color(50, 117, 1),
new Color(65, 159, 0), new Color(88, 201, 5),
new Color(107, 242, 2)
;
letterPanel = new LetterPanel[word.length()];
for (int i = 0; i < word.length(); i++)
letterPanel[i] = new LetterPanel(colors[i],
word.charAt(i));
panel.add(letterPanel[i]);
return panel;
public void updateWordPanel(String word)
for (int i = 0; i < word.length(); i++)
letterPanel[i].setLetter(word.charAt(i));
letterPanel[i].repaint();
private JPanel createControlPanel(String word)
JPanel panel = new JPanel();
String[] words = "ABLE", "BATH", "EXIT", "WORD" ;
wordComboBox = new JComboBox<>(words);
wordComboBox.setSelectedItem(word);
wordComboBox.addActionListener(new WordListener());
panel.add(wordComboBox);
leftBox = new JCheckBox("Left");
panel.add(leftBox);
rightBox = new JCheckBox("Right");
panel.add(rightBox);
JButton rotateButton = new JButton("Rotate");
rotateButton.addActionListener(new RotateListener());
panel.add(rotateButton);
JButton stopButton = new JButton("Stop");
stopButton.addActionListener(new StopListener());
panel.add(stopButton);
return panel;
public class LetterPanel extends JPanel
private static final long serialVersionUID = 1L;
private char letter;
private Color backgroundColor;
private Font font;
public LetterPanel(Color backgroundColor, char letter)
this.backgroundColor = backgroundColor;
this.letter = letter;
this.font = getFont().deriveFont(96f)
.deriveFont(Font.BOLD);
this.setPreferredSize(new Dimension(120, 200));
public void setLetter(char letter)
this.letter = letter;
@Override
protected void paintComponent(Graphics g)
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(backgroundColor);
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.setColor(Color.BLACK);
drawCenteredString(g2d, Character.toString(letter),
font);
/**
* Draw a String centered in the middle of the panel.
*
* @param g2d The Graphics2D instance.
* @param text The String to draw.
* @param font The Font to draw with.
*/
public void drawCenteredString(Graphics2D g2d,
String text, Font font)
FontMetrics metrics = g2d.getFontMetrics(font);
int x = (getWidth() - metrics.stringWidth(text)) / 2;
int y = ((getHeight() - metrics.getHeight()) / 2) +
metrics.getAscent();
g2d.setFont(font);
g2d.drawString(text, x, y);
public class WordListener implements ActionListener
@Override
public void actionPerformed(ActionEvent event)
word = (String) wordComboBox.getSelectedItem();
updateWordPanel(word);
public class RotateListener implements ActionListener
@Override
public void actionPerformed(ActionEvent event)
boolean leftSelected = leftBox.isSelected();
boolean rightSelected = rightBox.isSelected();
if (leftSelected && rightSelected)
word = "OOPS";
updateWordPanel(word);
return;
if (!leftSelected && !rightSelected)
return;
word = (String) wordComboBox.getSelectedItem();
updateWordPanel(word);
animation = new Animation(leftSelected);
new Thread(animation).start();
public class StopListener implements ActionListener
@Override
public void actionPerformed(ActionEvent event)
if (animation != null)
animation.setRunning(false);
animation = null;
public class Animation implements Runnable
private boolean leftSelected;
private volatile boolean running;
public Animation(boolean leftSelected)
this.leftSelected = leftSelected;
this.running = true;
@Override
public void run()
while (running)
updatePanel();
sleep(1000L);
if (leftSelected)
word = rotateLeft(word);
else
word = rotateRight(word);
public synchronized void setRunning(boolean running)
this.running = running;
private String rotateLeft(String word)
return word.substring(1) + word.substring(0, 1);
private String rotateRight(String word)
return word.substring(word.length() - 1) +
word.substring(0, word.length() - 1);
private void updatePanel()
SwingUtilities.invokeLater(new Runnable()
@Override
public void run()
updateWordPanel(word);
);
private void sleep(long duration)
try
Thread.sleep(duration);
catch (InterruptedException e)
// Deliberately left blank
【讨论】：
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