stopwatch.java

用java编写的一些初级代码

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.text.SimpleDateFormat;
class StW extends Canvas implements Runnable
{
    private long startTime =0;
    private long endTime = 0;
    private boolean bStart =false;
    public StW ()
    {
	enableEvents(AWTEvent.MOUSE_EVENT_MASK);
	setSize(80,30);
    }
    protected void processMouseEvent(MouseEvent e)
    {
	if(e.getID()==MouseEvent.MOUSE_PRESSED)
	{

	    bStart = true;
	    startTime = endTime =System.currentTimeMillis();
	    repaint();

	    new Thread(this).start();
	}
	else if (e.getID()==MouseEvent.MOUSE_RELEASED)
	{
	    bStart =false;
	    repaint();
	}
	super.processMouseEvent(e);
    }

    public void paint(Graphics g)
    {
	SimpleDateFormat sdf=new SimpleDateFormat("HH:mm:ss");
	Date elapsedTime = null;
	try
	{
	    elapsedTime=sdf.parse("00:00:00");
	}catch (Exception e){}
	elapsedTime.setTime(endTime-startTime+elapsedTime.getTime());

	String display =sdf.format(elapsedTime);
	g.drawRect(0,0,78,28);
	g.fill3DRect(2,2,75,25,true);
	g.setColor(Color.RED);
	g.drawString(display,10,20);
    }
    public void run()
    {
	while(bStart)
	{
	    try
	    {
		Thread.sleep(500);
	    }catch (Exception e){e.printStackTrace();}
	    endTime = System.currentTimeMillis();
	    repaint();
	}
    }
}
public class StopWatch
{
    public static void main(String [] args)
    {
	Frame f= new Frame ("StopWatch");
	f.add(new StW());
	f.setSize(200,200);
	f.setVisible(true);
	f.addWindowListener(new WindowAdapter (){
    public void windowClosing (WindowEvent e)
    {
	e.getWindow().setVisible(false);
	((Window)e.getComponent()).dispose();
	System.exit(0);
    }
	}
	    
	    );
    }
}