在Java中为面板添加颜色选择器

Question

我创建了一个乒乓游戏，我想在其中实现一个颜色选择器，这样用户就可以选择他们想要的背景颜色。然而，即使我能够实现颜色选择器按钮，我也无法更改背景颜色。此外，由于这是一个面板，我无法使用setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);，因此在进入颜色选择器菜单后，我无法返回游戏。我还尝试制作一个新的Frame类，但它只是打开了一个单独的面板，不会改变现有面板的颜色。非常感谢您的帮助！提前感谢！

import java.awt.BorderLayout;
import javax.swing.JFrame;
public class Main{
public static void main(String[] args) {
JFrame frame = new JFrame("Pong");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
PongPanel pongPanel = new PongPanel();
frame.add(pongPanel, BorderLayout.CENTER);

frame.setSize(500, 500);
frame.setVisible(true);

// new JPanelBackgroundColorTest();
}

}

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener;  
import javax.swing.JPanel;
import javax.swing.Timer;
import java.awt.FlowLayout; 
import java.awt.event.*; 
import javax.swing.*;
public class PongPanel extends JPanel implements ActionListener, KeyListener {
private boolean showTitleScreen = true;
private boolean playing = false;
private boolean gameOver = false;
private boolean upPressed = false; 
private boolean downPressed = false; 
private boolean rightPressed = false; 
private boolean leftPressed = false; 
private boolean wPressed = false; 
private boolean sPressed = false; 
private boolean aPressed = false; 
private boolean dPressed = false; 
private int ballX = 250;
private int ballY = 250;
private int diameter = 20;
private int ballDeltaX = -1;
private int ballDeltaY = 3; 
private int playerOneX = 25;
private int playerOneY = 250;
private int playerOneWidth = 10;
private int playerOneHeight = 50;
private int playerTwoX = 465;
private int playerTwoY = 250;
private int playerTwoWidth = 10;
private int playerTwoHeight = 50;
private int paddleSpeed = 5; 
private int playerOneScore = 0;
private int playerTwoScore = 0;
JButton button;
JLabel label;




public PongPanel(){

this.setLayout(new FlowLayout());

button = new JButton("Pick a color");
button.addActionListener(this);

label = new JLabel();
label.setBackground(Color.white);

label.setOpaque(true);

this.add(button);
this.add(label);

this.setVisible(true);




setBackground(Color.BLACK);
setFocusable (true);
addKeyListener(this); 
Timer timer = new Timer(1000/60, this);
timer.start();


}



public void actionPerformed(ActionEvent e) {
step();
if(e.getSource()==button) {
JColorChooser colorChooser = new JColorChooser();

Color color = JColorChooser.showDialog(null, "Pick a color", Color.black);

label.setBackground(color);
}
}
public void step() {
if (playing) {
if(upPressed) {
if (playerOneY-paddleSpeed>0) {
playerOneY -= paddleSpeed;
}
}
if(rightPressed) {
if (playerOneX+paddleSpeed+playerOneWidth<getWidth()) {
playerOneX += paddleSpeed;
}
}
if (downPressed) {
if (playerOneY+paddleSpeed+playerOneHeight<getHeight()) {
playerOneY += paddleSpeed;
}
}
if (leftPressed) {
if (playerOneX-paddleSpeed>0) {
playerOneX -= paddleSpeed;
}
}
if (wPressed) {
if (playerTwoY-paddleSpeed>0) {
playerTwoY -= paddleSpeed;
}
}
if (dPressed) {
if (playerTwoX+paddleSpeed+playerTwoWidth<getWidth()) {
playerTwoX += paddleSpeed;
}
}
if (sPressed) {
if (playerTwoY+paddleSpeed+playerTwoHeight<getHeight()) {
playerTwoY += paddleSpeed;
}
}
if (aPressed) {
if (playerTwoX-paddleSpeed>0) {
playerTwoX -= paddleSpeed;
}
}
int nextBallLeft = ballX + ballDeltaX;
int nextBallRight = ballX + diameter + ballDeltaX;
int nextBallTop = ballY + ballDeltaY;
int nextBallBottom = ballY + diameter + ballDeltaY; 
int playerOneRight = playerOneX + playerOneWidth;
int playerOneTop = playerOneY;
int playerOneBottom = playerOneY + playerOneHeight;
float playerTwoLeft = playerTwoX; 
float playerTwoTop = playerTwoY; 
float playerTwoBottom = playerTwoX + playerTwoHeight; 
if (nextBallTop < 0 || nextBallBottom > getHeight()) {
ballDeltaY *= -1; 
}
if (nextBallLeft < playerOneRight) {
if (nextBallTop > playerOneBottom || nextBallBottom < playerOneTop) {
playerTwoScore ++;
if (playerTwoScore == 3) {
playing = false;
gameOver = true;
}
ballX = 250;
ballY = 250;
}
else {
ballDeltaX *= -1; 
}
}
if (nextBallRight > playerTwoLeft) {
if (nextBallTop > playerTwoBottom || nextBallBottom < playerTwoTop) {
playerOneScore ++;
if (playerOneScore == 3) {
playing = false;
gameOver = true;
}
ballX = 250;
ballY = 250;
}
else {
ballDeltaX *= -1; 
}
}
ballX += ballDeltaX; 
ballY += ballDeltaY; 
}
repaint(); 
}
public void paintComponent (Graphics g) {
super.paintComponent (g); 
g.setColor (Color.WHITE); 
if (showTitleScreen) {
g.setFont(new Font(Font.DIALOG, Font.BOLD, 36));
g.setFont(new Font(Font.DIALOG, Font.BOLD, 36));
g.drawString("Pong", 165, 100);
g.setFont(new Font(Font.DIALOG, Font.BOLD, 18));
g.drawString("Press 'P' to play.", 175, 400);
g.drawString ("Press 'Q' to quit.", 175, 450); 
}
else if (playing) {
int playerOneRight = playerOneX + playerOneWidth;
int playerTwoLeft = playerTwoX;
for (int lineY = 0; lineY < getHeight(); lineY += 50) {
g.drawLine(250, lineY, 250, lineY+25);
}
g.drawLine(playerOneRight, 0, playerOneRight, getHeight());
g.drawLine(playerTwoLeft, 0, playerTwoLeft, getHeight());
g.setFont(new Font(Font.DIALOG, Font.BOLD, 36));
g.drawString(String.valueOf(playerOneScore), 100, 100);
g.drawString(String.valueOf(playerTwoScore), 400, 100);
g.fillOval (ballX, ballY, diameter, diameter); 
g.fillRect(playerOneX, playerOneY, playerOneWidth, playerOneHeight);
g.fillRect(playerTwoX, playerTwoY, playerTwoWidth, playerTwoHeight);
}
else if (gameOver) {
g.setFont(new Font(Font.DIALOG, Font.BOLD, 36));
g.drawString(String.valueOf(playerOneScore), 100, 100);
g.drawString(String.valueOf(playerTwoScore), 400, 100);
g.setFont(new Font(Font.DIALOG, Font.BOLD, 36));
if (playerOneScore > playerTwoScore) {
g.drawString("Player 1 Wins!", 165, 200);
}
else {
g.drawString("Player 2 Wins!", 165, 200);
}
g.setFont(new Font(Font.DIALOG, Font.BOLD, 18));
g.drawString("Press space to restart.", 150, 400);
}
}
public void keyTyped (KeyEvent e) {}
public void keyPressed (KeyEvent e) {
if (showTitleScreen) {
if (e.getKeyCode() == KeyEvent.VK_P) {
showTitleScreen = false; 
playing = true; 
}

}
else if (playing) {
if (e.getKeyCode() == KeyEvent.VK_UP) {
upPressed = true; 
}
else if (e.getKeyCode() == KeyEvent.VK_DOWN) {
downPressed = true; 
} 
else if (e.getKeyCode() == KeyEvent.VK_LEFT) {
leftPressed = true; 
} 
else if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
rightPressed = true; 
} 
else if (e.getKeyCode()==KeyEvent.VK_W) {
wPressed = true; 
}
else if (e.getKeyCode()==KeyEvent.VK_S) {
sPressed = true; 
}
else if (e.getKeyCode()==KeyEvent.VK_A) {
aPressed = true; 
}
else if (e.getKeyCode()==KeyEvent.VK_D) {
dPressed = true; 
}
else if (e.getKeyCode() == KeyEvent.VK_Q) {
showTitleScreen = true; 
playing = false; 
}
}
else if (gameOver) {
if(e.getKeyCode() == KeyEvent.VK_SPACE) {
gameOver = false; 
showTitleScreen = true; 
playerOneY = 250; 
playerTwoY = 250; 
playerOneX = 25; 
playerTwoX = 465; 
ballX = 250; 
ballY = 250; 
playerOneScore = 0; 
playerTwoScore = 0; 
}
}
}
public void keyReleased (KeyEvent e) {

if (e.getKeyCode()==KeyEvent.VK_UP) {
upPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_DOWN) {
downPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_LEFT) {
leftPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_RIGHT) {
rightPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_W) {
wPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_S) {
sPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_A) {
aPressed = false; 
}
else if (e.getKeyCode()==KeyEvent.VK_D) {
dPressed = false; 
}
}
}

Answer 1

从了解如何使用颜色选择器开始。

让JavaDocs也可用也是非常有用的。您会发现JColorChooser有几个JColorChooser#showDialog说服方法，它们将在对话框中为您显示选择器。

例如。。。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
setBorder(new EmptyBorder(16, 16, 16, 16));
JButton chooseColor = new JButton("Choose Color");
add(chooseColor);
chooseColor.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color color = JColorChooser.showDialog(TestPane.this, "Make a choice", Color.MAGENTA);
if (color != null) {
setBackground(color);
}
}
});
}
}
}

我还建议你熟悉如何制作对话框和如何使用CardLayout，这取决于你希望UI如何工作