Here is an Spinner subclass which overrides performClick() to show a dialog instead of a dropdown. No XML required. Give it a try, let me know if it works for you.
public class DialogSpinner extends Spinner {
public DialogSpinner(Context context) {
super(context);
}
@Override
public boolean performClick() {
new AlertDialog.Builder(getContext()).setAdapter((ListAdapter) getAdapter(),
new DialogInterface.OnClickListener() {
@Override public void onClick(DialogInterface dialog, int which) {
setSelection(which);
dialog.dismiss();
}
}).create().show();
return true;
}
}
For more information read this article: How To Make Android Spinner Options Popup In A Dialog