Android在绘图时获得背景色

我试图在绘制CardView元素的画布时更改背景色。所以我试图得到onDraw事件的背景色，但我没有得到

如何获得CardView onDaw活动的背景色

public class MyCardView extends CardView {
    public MyCardView(Context context) {
        super(context);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int bgColor = ???some method???;
        if(bgColor == 0) {
            setBackgroundColor(Color.RED);
        }
        super.onDraw(canvas);
    }
}

---

提示：避免在

onDraw（）中分配

public class MyCardView extends CardView {
    private Drawable background;
    private int color = Color.RED;

    public MyCardView(Context context) {
        super(context);
        background = ((View) this.getParent()).getBackground();
        if (background instanceof ColorDrawable) {
            color = ((ColorDrawable) background).getColor();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        setBackgroundColor(color);
        super.onDraw(canvas);
    }
}