android - Calling a fragment method inside a custom view -

so background i've tried call method have in fragment (that's hosting custom view) within custom view.

i've tried using interface , implementing in fragment. i've tried getting instance of fragment in customview , calling method way. whatever reason, null pointers both ways.

way #1

public surveyview(context context, attributeset attrs) {     super(context, attrs);     setorientation(vertical);     options = new arraylist<>();     //updatepolls interface.      updatepolls = new multiplechoicepollfragment(); } public interface updatepolls {     void update(); } 

then call method in onclicklistener:

v.setonclicklistener(new onclicklistener() {                         @override                         public void onclick(view v) {                             (int p = 0; p < options.size(); p++) {                                 if (options.get(p) == v) {                                     setanswers(p);                                     updatepolls.update();                                 }                             }                         }                     }); 

the method update() gets called in fragment , try display toast, returns null pointer.

way #2

get instance of fragment in customview's constructor , call method.

public surveyview(context context, attributeset attrs) {         super(context, attrs);         setorientation(vertical);         options = new arraylist<>();     myactivity = (appcompatactivity)context;                 myactivity.getfragmentmanager().findfragmentbytag("multiple_choice_poll_fragment");             myactivity.update(); } 

this returns null pointer....

my fragment is:

public class multiplechoicepollfragment extends fragment implements surveyview.updatepolls 

and method implement is:

@override public void update() {     toast.maketext(getactivity(), "success", toast.length_short).show(); } 

myactivity = (appcompatactivity)context;                 myactivity.getfragmentmanager().findfragmentbytag("multiple_choice_poll_fragment"); 

this work, need use getsupportfragmentmanager().