Set layout_anchor von FloatingActionButton zu ID des Elements von übergeordneten Layout

Question

Seine mögliche app:layout_anchor von FloatingActionButton auf ID des Elements von übergeordneten Layout?

VIEW_A

<android.support.design.widget.CoordinatorLayout> 

    <android.support.design.widget.AppBarLayout 
     android:id="@+id/app_bar">     <--- APP_BAR 
     ... 
    </android.support.design.widget.AppBarLayout> 

    <FrameLayout />         <--- VIEW_B 

</android.support.design.widget.CoordinatorLayout> 

VIEW_B

<LinearLayout> 

    <android.support.v4.widget.NestedScrollView> 
     ... 
    </android.support.v4.widget.NestedScrollView> 

    <android.support.design.widget.FloatingActionButton 
     app:layout_anchor="@id/app_bar" />   <--- SET APP_BAR 

</LinearLayout> 

Answer 1

Nein ist es nicht. Einfach dies zu tun:

<android.support.design.widget.CoordinatorLayout> 

<android.support.design.widget.AppBarLayout 
    android:id="@+id/app_bar">     <--- APP_BAR 
    ... 
</android.support.design.widget.AppBarLayout> 

<FrameLayout />         <--- VIEW_B 

<android.support.design.widget.FloatingActionButton 
    app:layout_anchor="@id/app_bar" />