int width=360;
    private Paint paint;
    private RectF rectf;

    public TaijiTu(Context context) {
        super(context);
        init();
    }



    public TaijiTu(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public TaijiTu(Context context, @Nullable 
 
AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    @Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(360,360);
        rectf 
 
= new RectF(0,0,360,360);

    }

    private void init() {
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStrokeWidth(5);
    }
    @Override
protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        huaYuan(canvas);
    }

    private void huaYuan(Canvas canvas) {
        paint
 
.setStyle(Paint.Style.FILL);
        paint.setColor(Color.WHITE);

        canvas.drawArc(rectf,270,180,true,paint);
        paint.setColor(Color.BLACK);
        canvas.drawArc(rectf,270,-180,true,paint);
        drawHalfCirCle(canvas);
    }
    private void drawHalfCirCle(Canvas canvas) {
        //畫上面黑色半圓
paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.BLACK);
        RectF blackHalfRect = new RectF(width/4,0,width/2+width/4,width/2);
        canvas.drawArc(blackHalfRect,270,180,true,paint);


        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.WHITE);
        RectF whiteHalfRect = new RectF(width/4,width/2,width/2+width/4,width);
        canvas.drawArc(whiteHalfRect,270,-180,true,paint);
        getxiao(canvas);
    }

    private void getxiao(Canvas canvas) {
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.BLACK);
        canvas.drawCircle(width/2,width/4*3,20,paint);

        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.WHITE);
        canvas.drawCircle(width/2,width/4,20,paint);
    }