java - Changing image source of an imageview in a different layout -

i can't find solution anywhere, i'm still quite new programming might simple question.

in mainactivity take position of viewpager. according position want change source of imageview placed in layout inflate in service. code keep getting nullpointerexception. need declare imageview differently because it's in different layout showed one?

 public void onclick(view view) {       pagenumber = viewpager.getcurrentitem();     imageview = (imageview) findviewbyid(r.id.filterview);      switch (pagenumber){         case 0: imageview.setimageresource(r.drawable.goghfilter);             break;         case 1: imageview.setimageresource(r.drawable.background3);             break; 

thanks help!

well remember class inflated layout find views in layout, try findbyid view not in layout cause errors. resolve this, define custom layout inflater, inflate layout image , used view inflated , perform findbyid on it.