android - Update Listview in Fragment , based on activity result . No result found anywhere -

i have activity , fragment in activity have button in action bar ,on button click dialog box popup , in have listview. if select item list , data goes fragment , , based on data activity fragment listview should shown

e.g. if select technology , technology id =1 should pass in query parameter , based on fragment listview should appear. everytime select different item list fragment listview should updated.

but problem not getting data in fragment , list not getting updated

mainactivity.java

 @override         public boolean onprepareoptionsmenu(menu menu) {             menuitem actionviewitem = menu.finditem(r.id.miactionbutton);             // retrieve action-view menu             view v = menuitemcompat.getactionview(actionviewitem);             // find button within action-view             button b = (button) v.findviewbyid(r.id.btncustomaction);             // handle button click here              b.setonclicklistener(new onclicklistener() {                  @override                 public void onclick(view v) {                     // todo auto-generated method stub                     showdialog(custom_dialog_id);                 }             });             return super.onprepareoptionsmenu(menu);         }          @override         public dialog oncreatedialog(int id) {              dialog dialog = null;              switch (id) {             case custom_dialog_id:                 dialog = new dialog(this);                 dialog.setcontentview(r.layout.dialoglayout);                 dialog.settitle("select category");                  dialog.setcancelable(true);                 dialog.setcanceledontouchoutside(true);                  dialog.setoncancellistener(new oncancellistener() {                      @override                     public void oncancel(dialoginterface dialog) {                      }                 });                  dialog.setondismisslistener(new ondismisslistener() {                      @override                     public void ondismiss(dialoginterface dialog) {                         // todo auto-generated method stub                      }                 });                  // prepare listview in dialog                 dialog_listview = (listview) dialog.findviewbyid(r.id.dialoglist);                 arrayadapter<string> adapter = new arrayadapter<string>(this,                         android.r.layout.simple_list_item_1, listcontent);                 dialog_listview.setadapter(adapter);                 dialog_listview.setonitemclicklistener(new onitemclicklistener() {                      @override                     public void onitemclick(adapterview<?> parent, view view,                             int position, long id) {                         // todo auto-generated method stub                          // = (int) parent.getitemidatposition(position);                          category_name = (string) parent.getitematposition(position);                          log.d("category name", category_name);                           if(category_name.equals("a"))                         {                             cat_id=1;                          }                         if(category_name.equals("b"))                         {                             cat_id=2;                         }                         if(category_name.equals("c"))                         {                             cat_id=3;                         }                         if(category_name.equals("d"))                         {                             cat_id=4;                         }                         if(category_name.equals("e"))                         {                             cat_id=5;                         }                         if(category_name.equals("f"))                         {                             cat_id=6;                         }                           log.d("id",""+cat_id);                          dismissdialog(custom_dialog_id);                     }                  });                  break;             }              return dialog;         }       public int getmydata() {             return cat_id;         } 

fragment.java :

 public string param;         public string url;         public int cat_id;           mainactivity activity = (mainactivity) getactivity();             int mydatafromactivity = activity.getmydata();              cat_id = mydatafromactivity;             log.d("category_id", "" + cat_id);               map<string, string> map1 = new hashmap<string, string>();                 param = "?cat_id=" + cat_id;                  //url fake , original url working fine.                 url = "http://www.abbcd.com/xyz/webservices/data/getalldata.php"                         + param;                  map1.put("url", url);                  new multipartrequester(mainactivity, map1,                         netutils.requestcode.get_all_data,                         this).execute(); 

updated part :

@override     public void updatefragmentlist(int catid) {         // todo auto-generated method stub          param = "?cat_id=" + catid;          url = "http://www.abbcd.com/xyz/webservices/data/getalldata.php"+ param;          map<string, string> map1 = new hashmap<string, string>();         map1.put("url", url);          new multipartrequester(mainactivity, map1,                 netutils.get_data, this)                 .execute();     } 

the approach communication between activity , fragment listeners. when want update fragment, use listener , update fragment. create interface in mainactivity

listener

public interface fragmentlistener {         void updatefragmentlist(int catid); } 

implement in fragment

public class myfragment extends fragment implements mainactivity.fragmentlistener 

then in onactivitycreated of fragment

@override     public void onactivitycreated(bundle savedinstancestate) {         super.onactivitycreated(savedinstancestate);          ((mainactivity) getactivity()).setfragmentlistener(this); } 

mainactivity

public void setfragmentlistener(fragmentlistener listener)     {              this.fragmentlistener = listener;      }  public void senddatatofragment(int catid) {       this.fragmentlistener.updatefragmentlist(catid); } 

hope helps.

update

sending data fragment using this.fragmentlistener.updatefragmentlist(catid);, create method in fragment ``

public void updatefragmentlist(int catid){        //here update listview cat id }