Last evening I learnt how to make android2.1 support actionbar from Android Developers.The page is HERE,Click.
To sum up , I briefy illustrate the main steps:
1.Add the v7 appcompat library , which is not just a jar file but a library with resources.
2.Let the Activities that originally extending "Activity" to extend "ActionBarActivity".
3.In your manifest file, update either the <application> element
or individual <activity> elements
to use one of the Theme.AppCompat themes.
For example:
That‘s it.
BTW,if you wanna know what the Theme.AppCompat themes contain, "Alt + /" is not capable , you can find them also on Android Developers,
Thme.AppCompat.For example, you find
then you should change the theme like this:
android:theme="@style/Theme.AppCompat.Light.DarkActionBar"
keep in mind that the first letter in each word should be its upper class form.
Android Developers says the most important buttons should be set on the ActionBar, buttons that are not so important should be placed in the Overflow Button.
------Met a Problem----
After adding a key-value pair in strings.xml file, MainActivity.java pointed out that R.java can‘t be found.So open "gen" folder,sure enough R.java is missing.Checking the xml file,I found in <string name="action_search">Search!!</string>, the "s" in the string was written as a upper class form.change it back to lower, R.java returned.Problem solved.
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Learning Android ActionBar,布布扣,bubuko.com
原文：http://www.cnblogs.com/larrylawrence/p/3649741.html