自定义View 绘制一个简单的时钟

一.自定义类继承View

二.思考啊...

算啦，直接上砖头吧

自定义View界面:

public class MyClockView extends View {
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //todo 获取时间
            getTime();
            //todo 重新绘制
            invalidate();
            //todo 发送请求
            handler.sendEmptyMessageDelayed(1,1000);//每1000毫秒一请求
        }
    };
    private int Hours,Minutes,Seconds;//todo 定义时、 分、秒
    private int Width,Height;
    public MyClockView(Context context) {
        super(context);

    }

    public MyClockView(Context context, AttributeSet attrs) {
        super(context, attrs);
        getTime();//todo 获取时间方法

        handler.sendEmptyMessageDelayed(1,1000);//todo 发起请求
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();//todo 定义画笔
        paint.setColor(Color.BLACK);
        paint.setAntiAlias(true);
        paint.setStrokeWidth(5);
        paint.setTextSize(30);

        Width = getWidth();
        Height = getHeight();//获取 界面 宽 高
        // todo 绘制表盘
        paint.setStyle(Paint.Style.STROKE);
        canvas.drawCircle(Width/2,Height/2,Width/2-10,paint);

        //todo 绘制圆心
        paint.setStyle(Paint.Style.FILL_AND_STROKE);
        canvas.drawCircle(Width/2,Height/2,4,paint);

        //todo 绘制刻度
        for (int i = 0; i < 12; i++) {//todo 绘制小时刻度
            canvas.save();//保存
            canvas.rotate(360/12*(i+1),Width/2,Height/2);//旋转 （角度,X中心,Y中心）
            canvas.drawLine(Width/2,Height/2-Width/2+10,Width/2,Height/2-Width/2+50,paint);//刻度
            canvas.drawText((i+1)+"",Width/2-15,Height/2-Width/2+80,paint);//数字
            canvas.restore();//恢复
        }

        paint.setStrokeWidth(2);//重新 设置 画笔
        for (int i = 0; i < 60; i++) {//todo 绘制分钟刻度
            canvas.save();//保存
            canvas.rotate(360/60*(i+1),Width/2,Height/2);//旋转 （角度,X中心,Y中心）
            canvas.drawLine(Width/2,Height/2-Width/2+10,Width/2,Height/2-Width/2+30,paint);//刻度
            canvas.restore();//恢复
        }

        // TODO 绘制时针
        canvas.save();
        canvas.rotate(360/12*Hours+Minutes*0.5f,Width/2,Height/2);
        paint.setStrokeWidth(8);
        canvas.drawLine(Width/2,Height/2,Width/2,Height/2-Height/7,paint);
        canvas.restore();
        // TODO 绘制分针
        canvas.save();
        canvas.rotate(360/60*Minutes+Seconds*0.1f,Width/2,Height/2);
        paint.setStrokeWidth(5);
        canvas.drawLine(Width/2,Height/2,Width/2,Height/2-Height/5,paint);
        canvas.restore();
        // TODO 绘制秒针
        canvas.save();
        canvas.rotate(360/60*Seconds,Width/2,Height/2);
        paint.setStrokeWidth(3);
        paint.setColor(Color.RED);//设置分针颜色
        canvas.drawLine(Width/2,Height/2,Width/2,Height/2-Height/4,paint);
        canvas.restore();
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
    }

    public void getTime() {//todo 获取实时时间
        Calendar calendar = Calendar.getInstance();
        Hours = calendar.get(Calendar.HOUR);
        Minutes=calendar.get(Calendar.MINUTE);
        Seconds=calendar.get(Calendar.SECOND);
    }
}

布局页面:

    

<com.example.kjys.Taskapplication.MyClockView
    android:background="@android:color/holo_blue_light"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/custom_view_id"
/>

效果图: