layout_margin in CardView is not working properly

If you use RecyclerView to add CardView, android:layout_margin should be sufficient.

But using ListView to add CardView, you might do this:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content" >

<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="11dp"
    android:layout_marginRight="11dp"
    android:layout_marginTop="11dp">
       (other layout ...)
</android.support.v7.widget.CardView>

</FrameLayout>

But it is usually not the optimal one.