When I added appcompact v7 library to exising project, error occurs in xml file "error: Attribute "buttonBarStyle" has already been defined". See Screenshot
I downloaded the project sample form http://developer.oovoo.com/
When I added appcompact v7 library to exising project, error occurs in xml file "error: Attribute "buttonBarStyle" has already been defined". See Screenshot
I downloaded the project sample form http://developer.oovoo.com/
It sounds like your styleable is defined in your project RES folder. That styleable is also defined in the v7 support library, so it is now defined twice. Remove it from your RES xml.
See this answer and post: Build errors after adding fullscreen activity in Android Studio