[Java知识库]java多线程气球上升动画

有大佬看到的话希望帮忙解决一下注释的那三行，还有就是有什么更好的意见可以提出来，感谢！！


代码：

import javax.swing.*;
import java.awt.*;

public class imgUp extends JFrame {
    //定义一个背景图片
    ImageIcon background = new ImageIcon("img\\Blue.jpg");
    JLabel l = new JLabel(background);//将背景图片放入l标签
    //定义一个p面板
    JPanel p = new JPanel();
    //定义三个气球图片
    ImageIcon img1 = new ImageIcon("D:\\java\\MyThread\\img\\1.png");
    ImageIcon img2 = new ImageIcon("D:\\java\\MyThread\\img\\2.png");
    ImageIcon img3 = new ImageIcon("D:\\java\\MyThread\\img\\3.png");
    //同理将图片放入三个标签内
    JLabel lImg1 = new JLabel(img1);
    JLabel lImg2 = new JLabel(img2);
    JLabel lImg3 = new JLabel(img3);
    //因为三个图片大小相同，所以用一个代替便于线程run方法的使用
    int imgW = img2.getIconWidth();
    int imgH = img2.getIconHeight();

    public void init(JFrame frame,int width,int height){
        frame.setLocationRelativeTo(null);//窗口居中
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭窗口即退出程序
        frame.setSize(width, height);//设置窗口大小
        Container contentPane = frame.getContentPane();
        contentPane.setLayout(null);//空布局
        background.setImage(background.getImage().getScaledInstance(width,height,Image.SCALE_DEFAULT));//使图片按窗口大小缩放
        //下面也可以
//        Image img = background.getImage();
//        img = img.getScaledInstance(width,height,Image.SCALE_DEFAULT);
//        background.setImage(img);
        p.setSize(background.getIconWidth(),background.getIconHeight());//设置面板大小与背景图片大小相同
        p.add(l);//将有背景图片的标签l添加到p面板
        contentPane.add(lImg1);
        contentPane.add(lImg2);
        contentPane.add(lImg3);
        contentPane.add(p);//将p面板添加到容器中
        frame.setVisible(true);
        //定义一个Runnable接口对象
        Runnable r = new Runnable() {
            int runY = 100;//初始的纵坐标
            @Override
            public void run() {
                while (true){
                    try {
                        if (runY>-imgH){
                            switch (Thread.currentThread().getName()){
                                case "img1":lImg1.setBounds(20,runY--,imgW, imgH);break;
                                case "img2":lImg2.setBounds(100,runY--,imgW, imgH);break;
                                case "img3":lImg3.setBounds(180,runY--,imgW, imgH);break;
                            }
                        }else{
                            runY = height-imgH;
                        }
                        Thread.sleep(100);//休息0.1秒
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        };
        //定义三个线程对象
        Thread t1 = new Thread(r,"img1");
        Thread t2 = new Thread(r,"img2");
        Thread t3 = new Thread(r,"img3");
        //启动线程
        t1.start();
        t2.start();
        t3.start();
    }
    public static void main(String[] args) {
        imgUp i = new imgUp();
        //调用init方法
        i.init(new JFrame(),500,300);
    }
}

效果图：

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