练手java GUI(三)
自定义组件（计时器）：
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package gui.test06;import java.awt.AWTEvent;import java.awt.Canvas;import java.awt.Color;import java.awt.Graphics;import java.awt.event.MouseEvent;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;public class StopWatch extends Canvas implements Runnable {long startTime = 0;long endTime = 0;//线程标志状态private boolean bStart;public StopWatch() {//enableEvents(AWTEvent.MOUSE_EVENT_MASK);}public void paint(Graphics g) {SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");Date elapsedTime = null;try {elapsedTime = sdf.parse("00:00:00");} catch (ParseException e) {e.printStackTrace();}elapsedTime.setTime(elapsedTime.getTime() + endTime - startTime);String strTime = sdf.format(elapsedTime);g.fill3DRect(0, 0, 78, 28, false);g.setColor(Color.WHITE);g.drawString(strTime, 10, 20);}@Overrideprotected void processMouseEvent(MouseEvent e) {if (e.getID() == MouseEvent.MOUSE_PRESSED) {startTime = endTime = System.currentTimeMillis();bStart = true;//新启动一个线程去跑new Thread(this).start();} else if (e.getID() == MouseEvent.MOUSE_RELEASED) {endTime = System.currentTimeMillis();bStart = false;}repaint();}@Overridepublic void run() {while (bStart) {try {Thread.sleep(500);} catch (InterruptedException e) {e.printStackTrace();}endTime = System.currentTimeMillis();repaint();}}}?