Android Change textView text from another method/class -
after click on button1, layout , class gets called. want change text of textview out of class 2 results in app crash java.lang.nullpointerexception important parts of class 1 public static textview a; protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); [button stuff in class 1] setcontentview(r.layout.raten); final textview = (textview) findviewbyid(r.id.a); //the textview wanna chage max = 10; easy easy = new easy(); // other class easy.e(); [now method in class 1 should change text] public static void tx(int i) { a.settext("adsfasdf"); } [important parts of class 2 ("easy")] public void e(){ system.out.println("called class easy"); int max = mainactivity.max; system.out.println(max); (int i= 0; i<max; i++){ syste...