How to attach an xml layout resource file with spinner adaptor in creation

Question

Here is my code

enter code here
ArrayAdapter<String> aa=new ArrayAdapter<String>(this,R.layout.spinnerLayout

           android.R.layout.simple_list_item_1,choicesString);
           aa.setDropDownViewResource(
           android.R.layout.simple_spinner_dropdown_item);
           newQuestionSpinner.setAdapter(aa);

The R.layout.spinnerLaout is producing null pointer exception How to attach the xml resource file with it