animatordemo.java

本java源程序包括了大量的学习程序（共27章）方便大家学习

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class AnimatorDemo extends JFrame implements ActionListener
{
	private AnimatorPanel animatorPanel;   //绘制动画的面板
	private JButton startButton, stopButton;
	private JPanel buttonPanel;      //存放开始按钮和结束按钮的面板
	
	public AnimatorDemo()
	{
		super("getImage");
	    setSize(400, 400);
	    
	    //获取内容面板
	    Container container = getContentPane();
	    
	    //创建用于绘制图像的面板
	    animatorPanel = new AnimatorPanel();
	    container.add(animatorPanel, BorderLayout.CENTER);
	    
	    //创建按钮
	    startButton = new JButton("开始");
	    stopButton = new JButton("停止");
	    stopButton.setEnabled(false);
	    //设置字体
	    Font font = new Font("Serif", Font.PLAIN, 14);
	    startButton.setFont(font);
	    stopButton.setFont(font);
	    //注册监听器
	    startButton.addActionListener(this);
	    stopButton.addActionListener(this);
	    //创建存放开始和停止按钮的面板
	    buttonPanel = new JPanel();
	    buttonPanel.add(startButton);
	    buttonPanel.add(stopButton);
	    
	    container.add(buttonPanel, BorderLayout.SOUTH);
	    
	    setVisible(true);
	    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	//处理按钮事件
	public void actionPerformed(ActionEvent event)
	{
		if(event.getSource() == startButton)
			animatorPanel.start();
		else if(event.getSource() == stopButton)
			animatorPanel.stop();
	}
	
	public static void main(String[] args) 
	{
		AnimatorDemo application = new AnimatorDemo();
	}

    class AnimatorPanel extends JPanel implements ActionListener
    {
    	private ImageIcon images[];
    	private int currentImage = 0;     //当前帧
    	private Timer timer;              //定时器
    	private int x = -100, y;                 //图像的坐标
    	
        public AnimatorPanel() 
        {
        	super();
        	setBackground(Color.WHITE);
        	images = new ImageIcon[4];    //创建图像对象数组
        	for(int i = 0; i < images.length; i++)
        	{        //载入图像
        		images[i] = new ImageIcon("boy0" + (i+1) + ".png");
        	}
        }
        
        public void paintComponent(Graphics g) 
        {
            Graphics2D g2d=(Graphics2D)g;
            g2d.setColor(getBackground());
            g2d.fillRect(0, 0, getWidth(), getHeight());
            //绘制图像,坐标为屏幕中心 
            y = (this.getHeight() - images[currentImage].getIconHeight())/2;
            images[currentImage].paintIcon(this, g, x, y);
            //定时器正在运行
            currentImage = (++currentImage)%4; 
        }
        //开始动画
        public void start()
        {
        	if(timer == null)
        	{
        		currentImage = 0;
        		timer = new Timer(100, this);      //创建定时器
        		timer.start();
        	} 
        	else if(!timer.isRunning())
        		timer.restart();
        	startButton.setEnabled(false);
        	stopButton.setEnabled(true);
        }
        //动画暂停
        public void stop()
        {
        	timer.stop();
        	startButton.setEnabled(true);
        	stopButton.setEnabled(false);
        }
        
        //处理定时器事件
        public void actionPerformed(ActionEvent event)
        {
        	x += 10;
        	if(x >= 450)
        		x = -100;
        	repaint();
        }
    }
}