clock2.java

java编程实例

//Clock2.java
import java.util.*; 
import java.awt.*; 
import java.applet.*; 

public class Clock2 extends Applet implements Runnable { 
Thread timer = null; 
int lastxs=0, lastys=0, lastxm=0, lastym=0, lastxh=0, lastyh=0; 
Date dummy = new Date(); 
String lastdate = dummy.toLocaleString(); 

//初始化小程序
public void init() { 
int x,y; 
//设置时钟窗口的大小
resize(300,300); 
} 

//制作时钟界面
public void plotpoints(int x0, int y0, int x, int y, Graphics g) { 

g.drawLine(x0+x,y0+y,x0+x,y0+y); 
g.drawLine(x0+y,y0+x,x0+y,y0+x); 
g.drawLine(x0+y,y0-x,x0+y,y0-x); 
g.drawLine(x0+x,y0-y,x0+x,y0-y); 
g.drawLine(x0-x,y0-y,x0-x,y0-y); 
g.drawLine(x0-y,y0-x,x0-y,y0-x); 
g.drawLine(x0-y,y0+x,x0-y,y0+x); 
g.drawLine(x0-x,y0+y,x0-x,y0+y); 
} 

//画表盘
public void circle(int x0, int y0, int r, Graphics g) { 
	int x,y; 
	float d; 
	
	x=0; 
	y=r; 
	d=5/4-r; 
	plotpoints(x0,y0,x,y,g); 
	
	while (y>x){ 
		if (d<0) { 
		d=d+2*x+3; 
		x++; 
	} 
	else { 
		d=d+2*(x-y)+5; 
		x++; 
		y--; 
	} 
	plotpoints(x0,y0,x,y,g); 
	} 
} 


// 画屏函数
public void paint(Graphics g) { 
int xh, yh, xm, ym, xs, ys, s, m, h, xcenter, ycenter; 
String today; 
Date dat = new Date(); 

s = dat.getSeconds(); 
m = dat.getMinutes(); 
h = dat.getHours(); 
today = dat.toLocaleString(); 
xcenter=80; 
ycenter=55; 

xs = (int)(Math.cos(s * 3.14f/30 - 3.14f/2) * 45 + xcenter); 
ys = (int)(Math.sin(s * 3.14f/30 - 3.14f/2) * 45 + ycenter); 
xm = (int)(Math.cos(m * 3.14f/30 - 3.14f/2) * 40 + xcenter); 
ym = (int)(Math.sin(m * 3.14f/30 - 3.14f/2) * 40 + ycenter); 
xh = (int)(Math.cos((h*30 + m/2) * 3.14f/180 - 3.14f/2) * 30 + xcenter); 
yh = (int)(Math.sin((h*30 + m/2) * 3.14f/180 - 3.14f/2) * 30 + ycenter); 

//画表盘

g.setFont(new Font("TimesRoman", Font.PLAIN, 14)); 
g.setColor(Color.blue); 
circle(xcenter,ycenter,50,g); 
g.setColor(Color.darkGray); 
g.drawString("9",xcenter-45,ycenter+3); 
g.drawString("3",xcenter+40,ycenter+3); 
g.drawString("12",xcenter-5,ycenter-37); 
g.drawString("6",xcenter-3,ycenter+45); 

//重画

g.setColor(getBackground()); 
if (xs != lastxs || ys != lastys) { 
g.drawLine(xcenter, ycenter, lastxs, lastys); 
g.drawString(lastdate, 5, 125); 
} 
if (xm != lastxm || ym != lastym) { 
g.drawLine(xcenter, ycenter-1, lastxm, lastym); 
g.drawLine(xcenter-1, ycenter, lastxm, lastym); } 
if (xh != lastxh || yh != lastyh) { 
g.drawLine(xcenter, ycenter-1, lastxh, lastyh); 
g.drawLine(xcenter-1, ycenter, lastxh, lastyh); } 
g.setColor(Color.darkGray); 
g.drawString(today, 5, 125); 
g.drawLine(xcenter, ycenter, xs, ys); 
g.setColor(Color.blue); 
g.drawLine(xcenter, ycenter-1, xm, ym); 
g.drawLine(xcenter-1, ycenter, xm, ym); 
g.drawLine(xcenter, ycenter-1, xh, yh); 
g.drawLine(xcenter-1, ycenter, xh, yh); 
lastxs=xs; lastys=ys; 
lastxm=xm; lastym=ym; 
lastxh=xh; lastyh=yh; 
lastdate = today; 
} 

public void start() { 
if(timer == null) 
{ 
timer = new Thread(this); 
timer.start(); 
} 
} 

public void stop() { 
timer = null; 
} 

public void run() { 
while (timer != null) { 
try {Thread.sleep(100);} catch (InterruptedException e){} 
repaint(); 
} 
timer = null; 
} 

public void update(Graphics g) { 
paint(g); 
} 
}