如何能让程序正常运行并且显示面板，请在基础上添加程序！

[朗晴]

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

class TestStopWatch extends Frame
{
	public TestStopWatch()
	{
		this.add(new StopWatch());	
		addWindowListener(new WindowAdapter()
		{
			public void WindowClosing(WindowEvent e)
			{
				dispose();
				System.exit(0);
			}
		});
	}
	public static void main(String []args)
	{
		TestStopWatch sw=new TestStopWatch();
	}
}

import java.awt.*;
import java.awt.Canvas;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.awt.event.*;

public class StopWatch extends Canvas implements Runnable
{
	long startTime=0;
	long endTime=0;
	boolean start=false;
	public StopWatch()
	{
		enableEvents(AWTEvent.MOUSE_EVENT_MASK);
	}
	protected void processMouseEvent(MouseEvent e)
	{
		if(e.getID()==MouseEvent.MOUSE_CLICKED)
		{
			startTime=endTime=System.currentTimeMillis();
			repaint();
			start=true;
			new Thread(this).start();
		}else if(e.getID()==MouseEvent.MOUSE_RELEASED)
		{
			endTime=System.currentTimeMillis();
			repaint();
			start=false;
		}
	}
	public void paint(Graphics g)
	{
		SimpleDateFormat sdf=new SimpleDateFormat("HH:mm:ss");
		Date date=null;
		try
		{
			date=sdf.parse("00:00:00");
		}catch(Exception e)
		{
			e.printStackTrace();
		}
		date.setTime(date.getTime()+endTime-startTime);
		//new Date(endTime-startTime);
		String strName=sdf.format(date);
		g.fill3DRect(0,0,78,28,true);
		g.setColor(Color.WHITE);
		g.drawString(strName,10,20);
	}
	public void run()
	{
		while(start)
		{
			try
			{
				Thread.sleep(500);
			}catch(Exception e)
			{
				e.printStackTrace();
			}
			endTime=System.currentTimeMillis();
			repaint();
		}
	}
}

[周靖峰]

我帮你改了TestStopWatch，你主要是没有用setVisible将界面显示出来

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

class TestStopWatch extends Frame
{
    public TestStopWatch()
    {
        this.add(new StopWatch());    
        addWindowListener(new WindowAdapter()
	        {
	            public void windowClosing(WindowEvent e)	//这里写错了,你写成WindowClosing了
	            {
	                dispose();
	                System.exit(0);
	            }
	        });
    }
    public static void main(String []args)
    {
        TestStopWatch sw=new TestStopWatch();
        //下面还要加两句
        sw.setSize(400, 300);
        sw.setVisible(true);
    }
}