xmlns:toolsでAndroid Studioのレイアウトエディタを活用する ref: http://qiita.com/nein37/items/51935c5a691aa8a0d014

file0.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".MyActivity"

file1.xml

<string name="show_all_apps" tools:ignore="MissingTranslation">All</string>

file2.xml

<GridLayout tools:targetApi="ICE_CREAM_SANDWICH" >

file3.xml

<resources xmlns:tools="http://schemas.android.com/tools" tools:locale="es">

file4.xml

<android.support.v7.widget.GridLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".MainActivity"

file5.xml

<fragment android:name="com.example.master.ItemListFragment" tools:layout="@android:layout/list_content" />

file6.xml

 <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:listitem="@android:layout/simple_list_item_2" />

file7.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    tools:showIn="@layout/activity_main" />

file8.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:menu="menu1,menu2" />

file9.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:actionBarNavMode="tabs" />