In my app I've got a fragment which is called "About". On handhelds I want this fragment to look like a usual activity but on tablets I want it to be a dialog. Which way is preferred to handle this situation?
Make a style for this in your styles.xml (two styles.xml files, one in the values folder, the other in a values-large folder) but have the style you put in the values-large folder inherit from Theme.Dialog. Then have your fragment use that style. The system will take care of the rest.
Alternatively, make your class a DialogFragment, and then either embed it into a view hierarchy, or show it as a dialog, as explained here:
http://developer.android.com/reference/android/app/DialogFragment.html#DialogOrEmbed
来源：https://stackoverflow.com/questions/7593415/show-fragment-as-a-dialog-or-as-a-usual-activity