When you are using android.support.v4.app.FragmentManager then you should use getSupportFragmentManager() and if you are using android.app.FragmentManager then use getFragmentManager().
当你的Fragment继承于android.support.v4.app.FragmentManager时,使用getSupportFragmentManager();继承于android.app.FragmentManager使用getFragmentManager()
当Fragment和FragmentManager(以及FragmentTransaction)不匹配时,在使用fragmentTransaction.add()时可能会报错:cannot resolve method 'add(..)'
原文链接:http://stackoverflow.com/questions/25306197/using-getfragmentmanager-vs-getsupportfragmentmanager