Imagine, I have FragmentA from which I startDialogFragment (there are EditText in box). How to can I get back the value from the EditTex
You need to send the data from the dialog back to the activity via a callback method, then have the activity give that data back to the fragment you want it to go to. Just a quick example:
public void datFromDialog(String data){
MyFragment mf = (MyFragment)getFragmentManager().findFragmentById(r.id.frag);
mf.iWantNewData(data);
}