Android如何创建一个三等分覆盖不同颜色背景的圆

一次参加面试的时候面试官问到了这样的一个问题，如何自定义一个view然后实现三等分圆并覆盖不同颜色背景，当时就尴尬了。如果直接画一个圆覆盖同一种颜色肯定是没问题，三等分实在是没接触过，后来才知道原来Canvas直接提供了画扇形的方法，直接画三个120度的扇形覆盖不同颜色这样就拼成了一个圆，源码如下，不细说了：

public class MyView2 extends View {
    private static final float RADIUS = 120f;
    private static final int[] COLORS = new int[]{0xFFF06292, 0xFF81C784, 0xFFE57373};

    private Paint mPaint;
    private Context mContext;

    public MyView2(Context context) {
        super(context);
        mContext = context;
    }

    public MyView2(Context context, AttributeSet attr) {
        super(context, attr);
        mContext = context;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        initPaint();
        drawUI(canvas);
    }

    private void initPaint() {
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setStyle(Paint.Style.FILL);
    }

    private void drawUI(Canvas canvas) {
        WindowManager windowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
        int h = windowManager.getDefaultDisplay().getHeight();
        int w = windowManager.getDefaultDisplay().getWidth();
        float start = 0f;
        for (int i = 0; i < COLORS.length; i++) {
            mPaint.setColor(COLORS[i]);
            RectF rectF = new RectF(w / 2 - 200, h / 2 - 200, w / 2 + 200, h / 2 + 200);
            canvas.drawArc(rectF, start, RADIUS, true, mPaint);
            start += RADIUS;
        }
    }

}