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.
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试):
问题:
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
