主题：[讨论]J2ME小程序——模拟时钟+数字时钟

import java.util.Calendar;
import java.util.TimeZone;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class Clock extends MIDlet {

    public static Clock instance;

    public Clock() {
        instance = this;
    }

    public void startApp() {
        Display.getDisplay(this).setCurrent(new MainScreen());
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
    }
}

class MainScreen extends Canvas {

    GetTime t = new GetTime();
    int out_r = 80;
    int in_r = 70;
    int centure = 5;
    int halfWidth = getWidth() / 2;
    int halfHeight = getHeight() / 2;
    public String getTime = "";
    int getSecond, getMinute, getHour;
    int secondX = 0, secondY = 0, minuteX, minuteY, hourX, hourY;
    float[] sin = {0, 0.10453F, 0.2079F, 0.309017F, 0.4067366F, 0.5F, 0.587785F, 0.669F,
        0.743145F, 0.80902F, 0.886F, 0.913545F, 0.9511F, 0.978148F, 0.99452F, 1
    };
    int sin0_r = 0;
    int cos90_r = 0;
    int sin30_r = (int) (sin[5] * 70);
    int cos60_r = (int) (sin[10] * 70);
    int sin60_r = (int) (sin[10] * 70);
    int cos30_r = (int) (sin[5] * 70);
    int sin90_r = in_r;
    int cos0_r = in_r;

    public MainScreen() {
        Thread thread = new Thread(t);
        thread.start();
    }

    protected void paint(Graphics g) {
        Clear(g);

        //模拟时钟，时钟表面
        g.setColor(0, 0, 255);
        g.fillArc(halfWidth - out_r, halfHeight - out_r, out_r * 2, out_r * 2, 0, 360);
        
        //时钟表面，时刻点
        g.setColor(255, 0, 0);

        g.fillArc(halfWidth + sin30_r - 2, halfHeight - cos60_r, 4, 4, 0, 360);
        g.fillArc(halfWidth + sin60_r - 2, halfHeight - cos30_r, 4, 4, 0, 360);
        g.fillArc(halfWidth + sin90_r - 2, halfHeight - cos90_r, 4, 4, 0, 360);

        g.fillArc(halfWidth + sin0_r - 2, halfHeight + cos0_r, 4, 4, 0, 360);
        g.fillArc(halfWidth + sin30_r - 2, halfHeight + cos60_r, 4, 4, 0, 360);
        g.fillArc(halfWidth + sin60_r - 2, halfHeight + cos30_r, 4, 4, 0, 360);

        g.fillArc(halfWidth - sin0_r - 2, halfHeight - cos0_r, 4, 4, 0, 360);
        g.fillArc(halfWidth - sin30_r - 2, halfHeight - cos60_r, 4, 4, 0, 360);
        g.fillArc(halfWidth - sin60_r - 2, halfHeight - cos30_r, 4, 4, 0, 360);

        g.fillArc(halfWidth - sin30_r - 2, halfHeight + cos60_r, 4, 4, 0, 360);
        g.fillArc(halfWidth - sin60_r - 2, halfHeight + cos30_r, 4, 4, 0, 360);
        g.fillArc(halfWidth - sin90_r - 2, halfHeight + cos90_r, 4, 4, 0, 360);

        //数字时钟,时间显示
        g.setColor(0, 0, 0);
        Font font = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE);
        g.setFont(font);

        int fontWidth = font.stringWidth(getTime);
        int fontHeight = font.getHeight();
        g.drawString(getTime, halfWidth + fontWidth / 2, halfHeight + out_r + fontHeight / 2, Graphics.TOP | Graphics.RIGHT);

        //模拟时钟，指针
        g.setColor(0, 0, 0);
        // 秒针
        g.drawLine(halfWidth, halfHeight, halfWidth + secondX, halfHeight + secondY);
        //分针
        g.fillTriangle(halfWidth + minuteY / 16, halfHeight - minuteX / 16, halfWidth - minuteY / 16, halfHeight + minuteX / 16, halfWidth + minuteX, halfHeight + minuteY);
        // 时针
        g.fillTriangle(halfWidth + hourY / 10, halfHeight - hourX / 10, halfWidth - hourY / 10, halfHeight + hourX / 10, halfWidth + hourX, halfHeight + hourY);
        //表心
        g.fillArc(halfWidth - centure / 2, halfHeight - centure / 2, centure, centure, 0, 360);
    }

    private void Clear(Graphics g) {
        g.setColor(255, 255, 255);
        g.fillRect(0, 0, getWidth(), getHeight());
    }

    class GetTime implements Runnable {

        int n = 0;
        int h = 0;
        int num = 0;

        public void run() {
            while (true) {
                //从系统中获取时间
                Calendar calendar = Calendar.getInstance(TimeZone.getDefault());
                calendar.set(Calendar.HOUR_OF_DAY, (calendar.get(Calendar.HOUR_OF_DAY) + 8) % 24);
                getTime = calendar.getTime().toString();
                getSecond = calendar.get(Calendar.SECOND);
                getMinute = calendar.get(Calendar.MINUTE);
                getHour = calendar.get(Calendar.HOUR);
                //秒针定位//可以将秒针，分针，时针的定位封装在一个方法中。
                if (getSecond < 15) {
                    secondX = (int) (sin[(getSecond % 16)] * (in_r - 10));
                    secondY = -(int) (sin[15 - (getSecond % 16)] * (in_r - 10));
                }
                if (getSecond >= 15 && getSecond < 30) {
                    secondX = (int) (sin[15 - (getSecond % 15)] * (in_r - 10));
                    secondY = (int) (sin[(getSecond % 15)] * (in_r - 10));
                }
                if (getSecond >= 30 && getSecond < 45) {
                    secondX = -(int) (sin[(getSecond % 15)] * (in_r - 10));
                    secondY = (int) (sin[15 - (getSecond % 15)] * (in_r - 10));
                }
                if (getSecond >= 45 && getSecond < 60) {
                    secondX = -(int) (sin[15 - (getSecond % 15)] * (in_r - 10));
                    secondY = -(int) (sin[(getSecond % 15)] * (in_r - 10));
                }
                // 分针定位
                if (getMinute < 15) {
                    minuteX = (int) (sin[(getMinute % 16)] * (in_r - 20));
                    minuteY = -(int) (sin[15 - (getMinute % 16)] * (in_r - 20));
                }
                if (getMinute >= 15 && getMinute < 30) {
                    minuteX = (int) (sin[15 - (getMinute % 15)] * (in_r - 20));
                    minuteY = (int) (sin[(getMinute % 15)] * (in_r - 20));
                }
                if (getMinute >= 30 && getMinute < 45) {
                    minuteX = -(int) (sin[(getMinute % 15)] * (in_r - 20));
                    minuteY = (int) (sin[15 - (getMinute % 15)] * (in_r - 20));
                }
                if (getMinute >= 45 && getMinute < 60) {
                    minuteX = -(int) (sin[15 - (getMinute % 15)] * (in_r - 20));
                    minuteY = -(int) (sin[(getMinute % 15)] * (in_r - 20));
                }
                //时针定位
                h = ((getHour) % 12) * 5;
                n=(int)(getMinute/12);
                num = h + n;
                if (num < 15) {
                    hourX = (int) (sin[(num % 16)] * (in_r - 30));
                    hourY = -(int) (sin[15 - (num % 16)] * (in_r - 30));
                }
                if (num >= 15 && num < 30) {
                    hourX = (int) (sin[15 - (num % 15)] * (in_r - 30));
                    hourY = (int) (sin[(num % 15)] * (in_r - 30));
                }
                if (num >= 30 && num < 45) {
                    hourX = -(int) (sin[(num % 15)] * (in_r - 30));
                    hourY = (int) (sin[15 - (num % 15)] * (in_r - 30));
                }
                if (num >= 45 && num < 60) {
                    hourX = -(int) (sin[15 - (num % 15)] * (in_r - 30));
                    hourY = -(int) (sin[(num % 15)] * (in_r - 30));
                }

                repaint();

                try {
                    Thread.sleep(500);
                } catch (Exception e) {
                }
            }
        }
    }
}

//指针的定位十分复杂，李老师有没有更好的方法为指针定位。

 

首先肯定你的认真态度，你真的不错！每次练习都坚持

其次，也肯定你的程序，写得相当不错，功能很完整

的确，指针定位比较复杂，不过，这里确有改进空间，下周课上会讲