很简单，修改styles.xml代码
<style
name="AppBaseTheme"
parent="android:Theme.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>
为：
<style name="AppBaseTheme" parent="android:Theme.Holo.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>
然后
AndroidManifest.xml文件中设置android:theme="@style/AppTheme"
<application
android:name=".AppContext"
android:allowBackup="true"
android:icon="@drawable/logo"
android:label="@string/app_name"
android:launchMode="singleTask"
android:screenOrientation="portrait"
android:theme="@style/AppTheme"
>
</application>
运行程序可观察前后对比效果