What's wrong with my include in RelativeLayout?

Question

I want to create an activity with a title bar at top and a navigation bar at bottom. I used include to include the title bar layout and the navigation bar layout into the main layout as below. But, as a result, both the title bar and navigation bar went to the top of the screen. Could someone tell me why? Thanks!

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/home_widget" android:layout_width="fill_parent"
android:layout_height="fill_parent" 
android:background="@drawable/background">

<include android:id="@+id/title_bar" layout="@layout/title_bar" 
    android:layout_alignParentTop="true"
/>
<include android:id="@+id/navigation_bar" layout="@layout/navigation_bar" 
    android:layout_alignParentBottom="true"/>
</RelativeLayout>

Edit: I didn't find the root cause. But the following works:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/home_widget" android:layout_width="fill_parent"
android:layout_height="wrap_content" 
android:background="@drawable/background">
<RelativeLayout android:layout_width="fill_parent"
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true"
    android:id="@+id/title_bar"

    >
    <include layout="@layout/title_bar" 
/>
    </RelativeLayout>

<RelativeLayout android:layout_width="fill_parent"
    android:layout_height="wrap_content" 
    android:layout_alignParentBottom="true"
    android:id="@+id/navigation_bar"
    >
<include layout="@layout/navigation_bar" 
    />
</RelativeLayout>

Answer 1

You have nothing to fill the space between the top and bottom bar by the looks of it.

As a side not I tend to use LinearLayout instead and use the layout_weight attribute in the following way;

title_bar & navigation_bar get layout_weight="0" and the content between the two gets layout_weight="1". This tells the layout manager to expand the content to fill the space between the two if your linear layout is;

title_bar content navigation_bar