http://developer.android.com/guide/topics/ui/actionbar.html
1，ActionBar的几种形式
2,使用ActionBar需要Activity开启了带ActionBar的主题
Theme.Holo
<activity android:theme="@style/Theme.AppCompat.Light" ... >
3，
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
<item android:id="@+id/action_search"
android:icon="@drawable/ic_action_search"
android:title="@string/action_search"
yourapp:showAsAction="ifRoom" />
...
</menu>
