Settings工程中，Settings -> Language &input 界面所对应的Java代码和Preference布局如下：

        <android_root>/packages/apps/Settings/src/com/android/settings/LanguageSettings.java

        <android_root>/packages/apps/Settings/res/xml/language_settings.xml

1、Settings -> Language & input ->  language

    在<android_root>/packages/apps/Settings/res/xml/language_settings.xml中，该模块的Preference布局为：

<PreferenceScreen    

    android:key="phone_language"     

    android:title="@string/phone_language" >    

    <intent android:action="android.intent.action.MAIN"     

        android:targetPackage="com.android.settings"     

        android:targetClass="com.android.settings.LocalePicker" />    

</PreferenceScreen>    

当用户点击 Settings -> Language & input -> language 时，将启动“com.android.settings.LocalePicker”的Activity。其对应的源代码为：

        <android_root>/packages/apps/Settings/src/com/android/settings/LocalePicker.java