drawrtest.java

在面板上用线程画圆。并隔时间改变颜色。

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

public class DrawrTest //implements WindowListener
{
	public static void main(String args[]){
		int col = 0;
		long millis = 0;
		if(col<2 || col>12){
			col = 2;
			millis = 1000;
			MyFrame frame = new MyFrame(col,millis);
			frame.setSize(400,350);
			frame.setVisible(true);
			frame.addWindowListener(new WindowAdapter(){
					public void windowClosing(WindowEvent e){
						System.exit(0);
					}
				});	
		}
		else{
			System.exit(0);
		}
	
	}	
}

class COval extends JPanel implements Runnable
{
	private final Color colors[]={Color.black,Color.red,Color.blue,Color.gray,Color.lightGray,
							Color.white,Color.cyan,Color.pink,Color.darkGray,Color.green,
							Color.orange,Color.magenta,Color.yellow};

	private long c_millis = 0;
	
	public COval(long millis){
		c_millis = millis;
		Thread t1 =  new Thread(this);
		t1.start();
	}
	
	public void paint(Graphics g){
		int i = 0;
		i = (int)(Math.random()*colors.length);
		g.setColor(colors[i]);
		g.fillOval(0,0,getSize().width,getSize().height);
	}
	
	public void run(){
		while(true){
			try{	
				this.repaint();
				Thread.sleep(c_millis);
			}
			catch(InterruptedException e){
				System.out.println (e);
			}
		}
	}	
	
}

class MyFrame extends JFrame 
{
	private COval p[];
	private long m_millis = 0;
	
	public MyFrame(int col,long millis){
		m_millis = millis;
		Container c = getContentPane();
		c.setLayout(new GridLayout(col,col));
		p = new COval[col*col];
		for (int i = 0; i<col*col; i++){
			p[i] = new COval(millis);
			c.add(p[i]);
		}
	}

}