如何使用清單來管理 Java 應用程式中的多個彈跳球？

Java 中的多個彈跳球

在Java 應用程式上繪製多個彈跳球可以透過使用列表儲存球並迭代來實現通過它來移動和繪製每個球。這是程式碼的修改版本：

import java.awt.*;
import javax.swing.*;
import java.util.ArrayList;
import java.util.List;

public class Ball extends JPanel implements Runnable {

    List<Ball> balls = new ArrayList<Ball>();   
Color color;
int diameter;
long delay;
private int x;
private int y;
private int vx;
private int vy;

public Ball(String ballcolor, int xvelocity, int yvelocity) {
    if(ballcolor == "red") {
        color = Color.red;
    }
    else if(ballcolor == "blue") {
        color = Color.blue;
    }
    else if(ballcolor == "black") {
        color = Color.black;
    }
    else if(ballcolor == "cyan") {
        color = Color.cyan;
    }
    else if(ballcolor == "darkGray") {
        color = Color.darkGray;
    }
    else if(ballcolor == "gray") {
        color = Color.gray;
    }
    else if(ballcolor == "green") {
        color = Color.green;
    }
    else if(ballcolor == "yellow") {
        color = Color.yellow;
    }
    else if(ballcolor == "lightGray") {
        color = Color.lightGray;
    }
    else if(ballcolor == "magenta") {
        color = Color.magenta;
    }
    else if(ballcolor == "orange") {
        color = Color.orange;
    }
    else if(ballcolor == "pink") {
        color = Color.pink;
    }
    else if(ballcolor == "white") {     
        color = Color.white;
    }
    diameter = 30;
    delay = 40;
    x = 1;
    y = 1;
    vx = xvelocity;
    vy = yvelocity;
}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D)g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    for (Ball ball : balls) {
        g.setColor(ball.color);
        g.fillOval(ball.x, ball.y, 30, 30); //adds color to circle
        g.setColor(Color.black);
        g2.drawOval(ball.x, ball.y, 30, 30); //draws circle
    }
}

public void run() {
    while(isVisible()) {
        try {
            Thread.sleep(delay);
        } catch(InterruptedException e) {
            System.out.println("interrupted");
        }
        for (Ball ball : balls) {
            ball.move();
        }
        repaint();
    }
}

public void move() {
    if(x + vx < 0 || x + diameter + vx > getWidth()) {
        vx *= -1;
    }
    if(y + vy < 0 || y + diameter + vy > getHeight()) {
        vy *= -1;
    }
    x += vx;
    y += vy;
}

private void start() {
    while(!isVisible()) {
        try {
            Thread.sleep(25);
        } catch(InterruptedException e) {
            System.exit(1);
        }
    }
    Thread thread = new Thread(this);
    thread.setPriority(Thread.NORM_PRIORITY);
    thread.start();
}

public static void main(String[] args) {
    Ball ball1 = new Ball("red",3,2);
    Ball ball2 = new Ball("blue",6,2);
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.getContentPane().add(ball1);
    f.getContentPane().add(ball2);
    f.setSize(400,400);
    f.setLocation(200,200);
    f.setVisible(true);
    ball1.start();
    ball2.start();
}
}

在此修改後的程式碼中：

1. balls 清單用於儲存 Ball 類別的實例。
2. PaintComponent 方法會迭代球列表並在面板上繪製每個球。
3. run 方法也會迭代瀏覽球列表並在重新繪製面板之前移動每個球。

使用清單的好處：

• 它允許您新增和刪除動態球。
• 您可以輕鬆控制球的數量應用程式。
• 清單管理對每個球的引用，簡化記憶體管理。

以上是如何使用清單來管理 Java 應用程式中的多個彈跳球？的詳細內容。更多資訊請關注PHP中文網其他相關文章！