java se

[八宝粥]

编写一个Java Applet程序，在Applet内部现实一个蓝色反弹球的程序。
通过mousePressed时间使该球开始运动，当球撞击Applet边框时，它应从边框弹回并以相反的方向运动。

[sdojqy1122]

import java.applet.Applet;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import java.util.List;

import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;

public class Main extends Applet implements Runnable,MouseListener{
    int x = 60, y = 100;
    int dx = 5, dy = 5;
    int rgb = 0;
    Color color = new Color((int)(Math.random() * 0xFFFFFF));

    public static void main(String[] args) {
        new Main();
    }

    public Main(){
        setSize(350, 350);
        setBackground(Color.gray);
        this.addMouseListener(this);
        this.setLayout(null);
        setVisible(true);
        
        
    }

    public void doColor() {
        rgb = (int)(Math.random()*0xFFFFFF);
        color = new Color(rgb);
    }

    public void run() {
        while (true) {
            if (x <= 0) {
                dx = -dx;
                dy = -dy;
                doColor();
            }else if ((x + 50) >= this.getWidth()) {
            	dx = -dx;
                dy = -dy;
                doColor();
            }
            if (y <= 0) {
            	dx = -dx;
                dy = -dy;
                doColor();
            }else if ((y + 50) >= this.getHeight()){
            	dx = -dx;
                dy = -dy;
                doColor();
            }
            x = x + dx;
            y = y + dy;
            try {
                Thread.sleep(50);
                repaint();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    public void paint(Graphics g) {
        Color c = g.getColor();
        g.setColor(color);
        g.fillOval(x, y, 50, 50);
        g.setColor(c);
    }
	
    @Override
	public void mouseClicked(MouseEvent e) {
		
	}

	@Override
	public void mousePressed(MouseEvent e){
		System.out.print(this);
		new Thread(this).start();
	}

	@Override
	public void mouseReleased(MouseEvent e) {
		
	}

	@Override
	public void mouseEntered(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void mouseExited(MouseEvent e) {
		
	}
}

仅供参考。

[八宝粥]

[Quote=引用 1 楼 的回复:]

Java code

import java.applet.Applet;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.e……
[/Quote]
谢谢你啊！程序算然有缺点但是还是给了我很大帮助

[八宝粥]

try again 能否解释哈为甚么这个接口没有写成适配器，我刚才写成了内部类的形式之后new Thread（this).start();报错为甚么？先谢过了

[sdojqy1122]

可以啊。多写一个类文件就是了，只是我那种，extends只能继承一个父类。

[八宝粥]

[Quote=引用 4 楼 的回复:]

可以啊。多写一个类文件就是了，只是我那种，extends只能继承一个父类。
[/Quote]

内部类监听的时候，this.addMouseListener(this)中第二个this报错，还有内部类中不能有new Thread（this）.start(this);不能启动线程

[sdojqy1122]

this指的是当前对象，你都写了内部类了，不能用this.就应该是这样的。
this.addMouseListener(this.new 内部类名());
东西别学死了。什么是对象你有点混淆。照你这样要求继承MouseAdapter就完美了？写成实现MouseListener就可以了。别把学习的重点搞反了。

[sdojqy1122]

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.*;

public class Main extends Applet implements Runnable{
    int x = 60, y = 100;
    int dx = 5, dy = 5;
    int rgb = 0;
    Color color = new Color((int)(Math.random() * 0xFFFFFF));
    final Thread moveThread;//加final
    public static void main(String[] args) {
        new Main();
    }

    public Main(){
    	moveThread = new Thread(this);
        setSize(350, 350);
        setBackground(Color.gray);
        this.addMouseListener(new MouseAdapter(){
			@Override
			public void mousePressed(MouseEvent e) {
				System.out.println(moveThread.getState().toString());
				if(moveThread.getState().equals(Thread.State.NEW)){
					  moveThread.start();
				}
			}
        });
        this.setLayout(null);
        setVisible(true);
    }

    public void doColor() {
        rgb = (int)(Math.random()*0xFFFFFF);
        color = new Color(rgb);
    }

    public void run() {
        while (true) {
            if (x <= 0) {
                dx = -dx;
                doColor();
            }else if ((x + 50) >= this.getWidth()) {
            	dx = -dx;
                doColor();
            }
            if (y <= 0) {
                dy = -dy;
                doColor();
            }else if ((y + 50) >= this.getHeight()){
                dy = -dy;
                doColor();
            }
            x = x + dx;
            y = y + dy;
            try {
                Thread.sleep(50);
                repaint();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    public void paint(Graphics g) {
        Color c = g.getColor();
        g.setColor(color);
        g.fillOval(x, y, 50, 50);
        g.setColor(c);
    }
}

[八宝粥]

[Quote=引用 7 楼 的回复:]

Java code

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.*;

public class Main extends Applet implements Runnabl……
[/Quote]

果然是高手啊！我刚开始学，今天算是学习了，谢谢指教