DialogFragment not resizing when keyboard shown

Be sure that the layout is inside a scroll view:

<ScrollView
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  -->your layout here 
</ScrollView>

and follow Dirk comment:

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      View view = inflater.inflate(R.layout.fragment_text_editor, container);

//add this line 
getDialog().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);

      //[add more custom code...]
      return view;
    }

I just use the following line in my DialogFragment:

getDialog().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);

And nothing else, see here full example:

    public class TextEditor extends DialogFragment {

    public TextEditor () {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_text_editor, container);

        //set to adjust screen height automatically, when soft keyboard appears on screen 
        getDialog().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);

        //[add more custom code...]
        return view;
    }
}

Set the windowSoftInputMode property to adjustNothing in the AndroidManifest.xml of the activities that use the dialog fragment.

<activity
    ...
    android:windowSoftInputMode="adjustNothing">
...

and onCreateDialog to hide the soft input:

...
Dialog dialog = builder.create();
dialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);
return dialog;
}

FYI: https://developer.android.com/training/keyboard-input/visibility.html#ShowOnStart