java - How to pass the name of the fragment to an Asynctask class? -

i have class works fine, because put name of fragment need receive information back... class call more 1 fragment need pass name parameter don't know how pass , how receive it.

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this async class

public class asyncfragment extends asynctask<string, void, string> {     subirfotos container;      public asyncfragment(subirfotos f) {         this.container = f;     }      @override     protected string doinbackground(string... params) {         try {             thread.sleep(3000); // takes 3 seconds           }catch(exception ex) {}         return "dni activo "+params[0]+  " " + params[1];      }      @override     protected void onpreexecute() {         super.onpreexecute();         container.showprogressbar();     }      @override     protected void onpostexecute(string result) {         super.onpostexecute(result);         // activity can null if thrown out android while task running!         if(container!=null && container.getactivity()!=null) {             container.populateresult(result);             container.hideprogressbar();             this.container = null;         }     } } 

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this fragment

public class subirfotos extends fragment {      private string userdni;     private textview textview;      view view;     string mresult;     asyncfragment mtask;      public subirfotos() {}      //el fragment ha sido creado     @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);      }     @override     public view oncreateview(layoutinflater inflater, viewgroup container,                              bundle savedinstancestate) {           view= inflater.inflate(r.layout.fragment_subirfotos, container, false);         // on configuration changes (screen rotation) want fragment member variables preserved         setretaininstance(true);         return view;     }      //la vista de layout ha sido creada y ya está disponible     @override     public void onviewcreated(view view, bundle savedinstancestate) {         super.onviewcreated(view, savedinstancestate);     }      //la vista ha sido creada y cualquier configuración guardada está cargada     @override     public void onviewstaterestored(bundle savedinstancestate) {         super.onviewstaterestored(savedinstancestate);     }      //el activity que contiene el fragment ha terminado su creación     @override     public void onactivitycreated(bundle savedinstancestate) {         super.onactivitycreated(savedinstancestate);         bundle bundle = getarguments();         userdni = bundle.getstring("userdni");         textview =(textview)getview().findviewbyid(r.id.textview);          ejecutarasync(userdni);          if(istaskrunning(mtask)) {             showprogressbar();         }else {             hideprogressbar();         }         if(mresult!=null) {             populateresult(mresult);         }         super.onactivitycreated(savedinstancestate);      }       //el fragment ha sido quitado de su activity y ya no está disponible     @override     public void ondetach() {         super.ondetach();     }      protected void ejecutarasync(string dato) {         mtask = new asyncfragment(this);         mtask.execute(dato );     }      public void showprogressbar() {         textview resultview = (textview)getactivity().findviewbyid(r.id.texturlcontent);         resultview.setvisibility(view.gone);         progressbar progress = (progressbar)getactivity().findviewbyid(r.id.progressbarfetch);         progress.setvisibility(view.visible);         progress.setindeterminate(true);     }      public void hideprogressbar() {         textview resultview = (textview)getactivity().findviewbyid(r.id.texturlcontent);         resultview.setvisibility(view.visible);         progressbar progress = (progressbar)getactivity().findviewbyid(r.id.progressbarfetch);         progress.setvisibility(view.gone);      }      public void populateresult(string s) {         textview resultview = (textview)getactivity().findviewbyid(r.id.texturlcontent);         resultview.settext(s);     }      protected boolean istaskrunning(asyncfragment task) {         if(task==null ) {             return false;         } else if(task.getstatus() == asyncfragment.status.finished){             return false;         } else {             return true;         }     }  } 

don't pass fragment name or reference. this:

1. create interface clients of asynctask subclass. interface can inside asynctask subclass.

       interface onresultslistener {          public void onresults(string results);     } 

2. the class should have reference listener.

       private onresultslistener mlistener; 

3. set reference in constructor of class.

       public myasynctask(onresultslistener listener) {         mlistener = listener;     } 

4. call listener's method on completion:

       @override     protected void onpostexecute(string result) {         if (mlistener != null) {             mlistener.onresults(result);         }     } 

   that "inversion of control" or "dependency injection" thing? did it.

5. your client create listener , start task

        onresultslistener listener = new myasynctask.onresultslistener() {           @override          public void onresults(string results) {              // here stuff want results          }      };       new myasynctask(listener).execute(); 

now each fragment can use same class , different things results.