问题
Actually there is no problem. Project compiles and runs. But I can't understand what is mean strikeout class name (Android Studio tells that there is deprecated code is used)

回答1:
Since the version 22.1.0, the class ActionBarActivity
is deprecated. You should use AppCompatActivity
.
Read here and here for more information.
回答2:
According to this video of Android Developers you should only make two changes

回答3:
android developers documentation says : "Updated the AppCompatActivity as the base class for activities that use the support library action bar features. This class replaces the deprecated ActionBarActivity."
checkout changes for Android Support Library, revision 22.1.0 (April 2015)
来源:https://stackoverflow.com/questions/29890530/actionbaractivity-is-deprecated