Drawable as Background for CardView

Question

the CardView ( android.support.v7.cardview ) stays white even though I set a backround drawable via android:backround - The documentation gives me the feeling that it should

Answer 1

for drawable or color just use:

cvSellerShopp.setBackgroundResource(R.drawable.ic_action_add_image);

for color use:

 cvSellerShopp.setCardBackgroundColor(R.color.colorPrimary);

but this one does not produce the intended results