所以我想让这个正方形从墙上弹开。我对编码还很陌生，但是我不明白为什么会这样。它似乎弹跳得很厉害，因为它完全颠倒了击球的方向，因此它在逻辑上不会弹跳。
但是，最令人沮丧的问题是它只会反弹一次。它从侧面弹跳一次，然后遇到第二堵墙时，它就跳入深渊。
以下是用于编写代码的代码段：
void moveTheBox() {
while (inside == true) {
if ((bigBoxX <= 0) || (bigBoxY <= 0) ||
(bigBoxX >= 600 - bigBoxSize) ||
(bigBoxY >= 600 - bigBoxSize)) {
bigBoxDeltaX = bigBoxDeltaX * -1;
bigBoxDeltaY = bigBoxDeltaY * -1;
while ((bigBoxX >= 0) || (bigBoxY >= 0) ||
(bigBoxX <= 600 - bigBoxSize) ||
(bigBoxY <= 600 - bigBoxSize)) {
bigBoxX = bigBoxX + bigBoxDeltaX;
bigBoxY = bigBoxY + bigBoxDeltaY;
repaint();
pause();
}
} else {
bigBoxX = bigBoxX + bigBoxDeltaX;
bigBoxY = bigBoxY + bigBoxDeltaY;
repaint();
pause();
}
}
}
编辑：我想通了您发布后4分钟。我修复了笨拙的弹跳和1弹跳的问题。
这是最终产品：
void moveTheBox() {
int i = 0;
while(i == 0){
if ((bigBoxX <= 0) || (bigBoxX >= 600-bigBoxSize)){
bigBoxDeltaX = bigBoxDeltaX * -1;
while((bigBoxX >= 0) || (bigBoxY >=0) || (bigBoxX <= 600-bigBoxSize) || (bigBoxY <= 600 - bigBoxSize)){
bigBoxX = bigBoxX + bigBoxDeltaX;
bigBoxY = bigBoxY + bigBoxDeltaY;
repaint();
pause();
break;
}
}else if ((bigBoxY <= 0) || (bigBoxY >= 600-bigBoxSize)){
bigBoxDeltaY = bigBoxDeltaY * -1;
while((bigBoxX >= 0) || (bigBoxY >=0) || (bigBoxX <= 600-bigBoxSize) || (bigBoxY <= 600 - bigBoxSize)){
bigBoxX = bigBoxX + bigBoxDeltaX;
bigBoxY = bigBoxY + bigBoxDeltaY;
repaint();
pause();
break;
}
}else{
bigBoxX = bigBoxX + bigBoxDeltaX;
bigBoxY = bigBoxY + bigBoxDeltaY;
repaint();
pause();
}
}
}
最佳答案
import java.awt.*;
import java.util.Formatter;
import javax.swing.*;
/**
* One ball bouncing inside a rectangular box.
* All codes in one file. Poor design!
*/
// Extends JPanel, so as to override the paintComponent() for custom rendering codes.
public class BouncingBallSimple extends JPanel {
// Container box's width and height
private static final int BOX_WIDTH = 640;
private static final int BOX_HEIGHT = 480;
// Ball's properties
private float ballRadius = 200; // Ball's radius
private float ballX = ballRadius + 50; // Ball's center (x, y)
private float ballY = ballRadius + 20;
private float ballSpeedX = 3; // Ball's speed for x and y
private float ballSpeedY = 2;
private static final int UPDATE_RATE = 30; // Number of refresh per second
/** Constructor to create the UI components and init game objects. */
public BouncingBallSimple() {
this.setPreferredSize(new Dimension(BOX_WIDTH, BOX_HEIGHT));
// Start the ball bouncing (in its own thread)
Thread gameThread = new Thread() {
public void run() {
while (true) { // Execute one update step
// Calculate the ball's new position
ballX += ballSpeedX;
ballY += ballSpeedY;
// Check if the ball moves over the bounds
// If so, adjust the position and speed.
if (ballX - ballRadius < 0) {
ballSpeedX = -ballSpeedX; // Reflect along normal
ballX = ballRadius; // Re-position the ball at the edge
} else if (ballX + ballRadius > BOX_WIDTH) {
ballSpeedX = -ballSpeedX;
ballX = BOX_WIDTH - ballRadius;
}
// May cross both x and y bounds
if (ballY - ballRadius < 0) {
ballSpeedY = -ballSpeedY;
ballY = ballRadius;
} else if (ballY + ballRadius > BOX_HEIGHT) {
ballSpeedY = -ballSpeedY;
ballY = BOX_HEIGHT - ballRadius;
}
// Refresh the display
repaint(); // Callback paintComponent()
// Delay for timing control and give other threads a chance
try {
Thread.sleep(1000 / UPDATE_RATE); // milliseconds
} catch (InterruptedException ex) { }
}
}
};
gameThread.start(); // Callback run()
}
/** Custom rendering codes for drawing the JPanel */
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g); // Paint background
// Draw the box
g.setColor(Color.BLACK);
g.fillRect(0, 0, BOX_WIDTH, BOX_HEIGHT);
// Draw the ball
g.setColor(Color.BLUE);
g.fillOval((int) (ballX - ballRadius), (int) (ballY - ballRadius),
(int)(2 * ballRadius), (int)(2 * ballRadius));
// Display the ball's information
g.setColor(Color.WHITE);
g.setFont(new Font("Courier New", Font.PLAIN, 12));
StringBuilder sb = new StringBuilder();
Formatter formatter = new Formatter(sb);
formatter.format("Ball @(%3.0f,%3.0f) Speed=(%2.0f,%2.0f)", ballX, ballY,
ballSpeedX, ballSpeedY);
g.drawString(sb.toString(), 20, 30);
}
/** main program (entry point) */
public static void main(String[] args) {
// Run GUI in the Event Dispatcher Thread (EDT) instead of main thread.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
// Set up main window (using Swing's Jframe)
JFrame frame = new JFrame("A Bouncing Ball");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new BouncingBallSimple());
frame.pack();
frame.setVisible(true);
}
});
}
}
请参考tutorial