问题
How does whatsapp implement its action bar?The latest updated version contains action bar which works perfect on android 2.2 and android 4.1 without any differences. Any ideas how they've achieved backward compatibility? The back button works on android 2.2 which i could not get working by any means.
回答1:
According to Androlyzer, Whatsapp uses ActionBarSherlock for their Action Bar, which allows them to have a consistent Action Bar on all Android 2.1+ devices
来源：https://stackoverflow.com/questions/15553274/action-bar-in-android-like-whatsapp