Android ActionBar 返回为NULL

AndroidBar返回为NULL。是因为values-v11和values-v14下面的style的主题的设置的原因。

在SDK 11的设备上，会使用第二处，SDK 14会使用第三处。

只需要将三个地方的主题分别设置就可以，结构如下：

values--------

<resources>

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    </style>

</resources>

values-v11--------

<resources>

    <!--
        Base application theme for API 11+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Holo.Light">
        <!-- API 14 theme customizations can go here. -->
        <item name="android:actionBarStyle">@style/my_actionbar_style</item>
    </style>

    <style name="my_actionbar_style" parent="@android:style/Widget.Holo.Light.ActionBar">
        <item name="android:background">#ff8c00</item>
        <item name="android:titleTextStyle">@style/AcBar_titleStyle</item>
        <item name="android:displayOptions">showTitle</item>
    </style>

    <style name="AcBar_titleStyle">
        <item name="android:textColor">#FFFFFF</item>
        <item name="android:textSize">20sp</item>
    </style>

    <style name="AppTheme" parent="AppBaseTheme"></style>
</resources>

values-v14--------

<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <!--
        Base application theme for API 14+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Holo.Light.DarkActionBar">
        <!-- API 14 theme customizations can go here. -->
        <item name="android:actionBarStyle">@style/my_actionbar_style</item>
    </style>

    <style name="my_actionbar_style" parent="@android:style/Widget.Holo.Light.ActionBar">
        <item name="android:background">#ff8c00</item>
        <item name="android:titleTextStyle">@style/AcBar_titleStyle</item>
         <item name="android:displayOptions">showTitle</item>
    </style>
    <style name="AcBar_titleStyle">
        <item name="android:textColor">#FFFFFF</item>
        <item name="android:textSize">20sp</item>
    </style>
    <style name="AppTheme" parent="AppBaseTheme"></style>
</resources>

主要注意红色部分