动态获取R.drawable.xx资源

                    String imageName = "index_fragmen"+getColor();
                    final int resId = context.getResources().getIdentifier(imageName, "drawable", context.getPackageName());
                    if (resId != 0) {
                        Log.e("mytest", "可以获取到");
                        holder.btnCoupon.setBackgroundResource(resId);
                    }