java - Android when fragment is removed -

i have framelayout , put there fragments click on button, next click should remove fragment framelayout, removeallviews() (framelayout in fragment translaction method in activity). need action when removeallviews() starts , have in fragment class goes wrong.

i tried: ondestroy() ondestroyview() onpause() in fragment class

but works like:

1. put fragment in framelayout (from activity)
2. use removeallviews() (from activity)
3. there no fragment in framelayout (is clear) nothing else happens , methods not working
4. put new fragment in framelayout (from activity) - methods (ondestroy() fragment class) works (probably it's real time destroy old fragment)

how possible 'get moment' when fragment not exists user? want send information server if user hides fragment.

@edit3 code method activity want make translaction

public void showproductslist(string producttype,int containerid){          list<string> prodnames = new arraylist<string>();         list<long> prodids = new arraylist<long>();              databasedaoprodprotein dao = new databasedaoprodprotein(getapplicationcontext());             dao.open();             list<databaseproduct> productlist = dao.getallproducts();             for(int i=0;i<productlist.size();i++){                 prodnames.add(productlist.get(i).getname());                 prodids.add(productlist.get(i).getid());             }             dao.close();          productslist productslist = new productslist(producttype,prodnames,prodids);          productslist.setonsystemuivisibilitychangelistener                 (new view.onsystemuivisibilitychangelistener() {                     @override                     public void onsystemuivisibilitychange(int visibility) {                         // note system bars "visible" if none of                         // low_profile, hide_navigation, or fullscreen flags set.                         toast.maketext(getapplicationcontext(),"action1 " ,toast.length_long).show();                         if ((visibility & view.system_ui_flag_fullscreen) == 0) {                             // todo: system bars visible. make desired                             // adjustments ui, such showing action bar or                             // other navigational controls.                             toast.maketext(getapplicationcontext(),"action2 " ,toast.length_long).show();                         } else {                             // todo: system bars not visible. make desired                             // adjustments ui, such hiding action bar or                             // other navigational controls.                             toast.maketext(getapplicationcontext(),"action3 " ,toast.length_long).show();                         }                     }                 });          fragmentmanager manager = getsupportfragmentmanager();         fragmenttransaction transaction = manager.begintransaction();         transaction.replace(containerid, productslist).commit();     } 

i used method in fragment by:

((mainactivity) getcontext()).showproductslist("carb", carbcontainer.getid());

there error:

error:(560, 21) error: cannot find symbol method setonsystemuivisibilitychangelistener(<anonymous onsystemuivisibilitychangelistener>)

you say:

"how possible 'get moment' when fragment not exists user? want send information server if user hides fragment."

i know did not mean "hide", use ondestroy() method.

try trigger "hide"

view toplevellayout = findviewbyid(r.id.top_layout); toplevellayout.setvisibility(view.invisible); 

you cannot go stopped state while fragment (activity) visible. android destroying activities, killing processes

the best way make sure runs via view run via post:

toplevellayout.post(new runnable() { @override public void run() {         toplevellayout.removeallviews();     } } 

to notified of system ui visibility changes, register view.onsystemuivisibilitychangelistener view (fragment).

https://developer.android.com/training/system-ui/visibility.html

@override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         toast.maketext(getcontext(),"action0 " ,toast.length_long).show();     fragment your_frag = new productslist(producttype,prodnames,prodids); getsupportfragmentmanager().begintransaction().replace(containerid,your_frag).commit();     getsupportfragmentmanager().executependingtransactions();//make sure oncreateview has executed         your_frag.getrootview().setonsystemuivisibilitychangelistener                 (new view.onsystemuivisibilitychangelistener() {                     @override                     public void onsystemuivisibilitychange(int visibility) {                         // note system bars "visible" if none of                         // low_profile, hide_navigation, or fullscreen flags set.                         toast.maketext(getcontext(),"action1 " ,toast.length_long).show();                         if ((visibility & view.system_ui_flag_fullscreen) == 0) {                             // todo: system bars visible. make desired                             // adjustments ui, such showing action bar or                             // other navigational controls.                             toast.maketext(getcontext(),"action2 " ,toast.length_long).show();                         } else {                             // todo: system bars not visible. make desired                             // adjustments ui, such hiding action bar or                             // other navigational controls.                             toast.maketext(getcontext(),"action3 " ,toast.length_long).show();                         }                     }                 });     }     

a typical fragment looks this:

public class homefragment extends fragment {     view                        mrootview     = null;     public homefragment(){}//null constructor      @override     public view oncreateview(layoutinflater inflater, viewgroup container,             bundle savedinstancestate) {          mrootview = inflater.inflate(r.layout.fragment_home, container, false);          return mrootview ;     } public view getrootview () {     return mrootview; } }