run.java

本程序是程序设计第五版课后习题,实现画圆,画直线,画矩形

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Run extends JPanel implements ActionListener
{
	JPanel  textJPanel = new JPanel();
	JLabel  label = new JLabel(" ");
	Timer time; 
	int x,y;
	
	Run()
	{
		setSize(800,20);
		setBackground(Color.white);
		label.setLocation(800,5);
		add(label);
		time = new Timer(10,this);
		time.start();
	}
	
	public void actionPerformed(ActionEvent e)
	{
		
		Rectangle rec = label.getBounds();
		x = (int)rec.getX();
		y = (int)rec.getY();
		x -= 2;
		if(x+400<0)x=800;
		label.setLocation(x,y);
		
	}
	       
}