android layout creation issue

Question

Am new to android development. I had created one android app and for that following is my main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:id="@+id/RelativeLayout01" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent"
android:background="@drawable/bg"
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout android:id="@+id/grid_layout_1"
    android:layout_centerInParent="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    >
    <Button android:id="@+id/btnLogin" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:text="@string/login_btn_text"/>
    <Button android:id="@+id/btnRegister" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:text="@string/reg_btn_text"/>

</LinearLayout>
</RelativeLayout>

Am getting the following warning :

This LinearLayout layout or its RelativeLayout parent is possibly useless;
transfer the background attribute to the other view

Can anyone tell the reason for this warning and a solution to the issue.?

Answer 1

There is no real usage to have just a LinearLayout inside a RelativeLayout. So one of them is useless as this is redundant.

edit

This warning is triggered, when a Layout has only one child that is also a Layout. In this case one of both can be removed without any problems. It is recommended to remove these redundant layouts as they reduce the overall performance of the UI.

Answer 2

The answer to your question, as I just discovered myself, is to disable the new Lint "help". I suppose it's helpful to someone just starting out in Android, but to anyone that knows what they're doing, it's just a nuisance. For example, your "useless" nested linear layout might very well be a button inside a padded layout that might be awaiting being filled by some other element, at run time (or a billion other, entirely valid things).

In your preferences, under android/lint, just disable the warnings and you won't see these warnings anymore.