How to transfer Android app from 1.6 to 2.x to tablet 3.0?
I made changes to the manifest file about targetSDK, but the application does not use components or the theme of the tablet. Why?
Take a look at a few pages in the document:
http://developer.android.com/guide/topics/ui/themes.html - in particular, the section "Choose a theme based on the platform version"
http://developer.android.com/guide/topics/ui/actionbar.html - see "Adding an action bar"
Are you adding a theme to your application that does not use one of the Holo themes?
(And closely related to your question: you also want to look at the compatibility library for Honeycomb features in 2.X and 1.6 applications)