使用Timer类的动画

程序清单

“`
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class AnimationDemo extends JFrame {

public AnimationDemo()
{
    add(new MovingMessagepanel("Message  moving"));
}

public static void main(String[] args)
{
    AnimationDemo frame=new AnimationDemo();
    frame.setTitle("AnimationDemo");
    frame.setSize(280,100);
    frame.setLocationRelativeTo(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}
static class MovingMessagepanel extends JPanel
{
    private String message ="Welcome to Java";
    private int xCoordinate=0;
    private int yCoordinate=20;


    public   MovingMessagepanel(String message)
    {
        this.message=message;


         Timer timer = new Timer(1000, new TimerListener());
        timer.start();
    }
    public  void paintComponent(Graphics g)
    {
        super.paintComponent( g);


        if(xCoordinate>getWidth())
        {
            xCoordinate=-20;
        }
        xCoordinate += 20;
         g.drawString(message,xCoordinate,yCoordinate);

    }
    class TimerListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            repaint();
        }
    }
}

}