How to add a screen-fixed element in Android?

Question

Android

How to add a screen-fixed element in Android? I have created a Toolbar with a menu that is located after the main content, I want to anchor it to the bottom of the screen. How can you check something like this?
What parameter should be given to this parent element to make its position fixed?

<android.support.v7.widget.Toolbar android:id="@+id/toolbar_bottom"
            android:layout_width="match_parent"
            android:textAlignment="center"
            android:layout_gravity="center"
            android:layout_height="?attr/actionBarSize"
            android:layout_alignParentBottom="true"
            android:background="?attr/colorPrimary"
            android:layout_below="@+id/toolbar">

Answer 1

Alternatively, using a vertical LinearLayout as the parent, lay out two elements in it:
*) Body\content, which has a height of 0dp and a weight (layout_weight) of 1
*) Your toolbar, fixed height.
After that, it should cling to the lower border.