android - Using list view in fragments -

i have drawer layout fragment (in main activity) shows expandable list, when click on sub-item of expanded item, popup window appears. pop window custom layout contains text views, list view , 2 buttons.

i gave list view id: android:id="@android:id/list" , return null viewgroup in oncreateview function follow:

public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {             view rootview = inflater.inflate(r.layout.fragment_settings, null); 

and make class extends fragment not listfragment

i did previous 3 steps avoid "content has view id attribute 'android.r.id.list' not listview class in listfragment" error

but still have nullpointerexception error pointing

faillistview.setadapter(adapter); 

when click on "failsafe setup" item

i've seen suggestions of them don't useful, rootview .findviewbyid?() not getactivity().findviewbyid() ==> i've it. or declaring list view before oncreateview function. annoyed this, i've tried lot of suggestions work others.

even though, i've tried add snippet onactivitycreated function

  testfailsafeadapter adapter = new testfailsafeadapter(getactivity().getapplicationcontext(),       r.layout.dialog,r.id.textview1,       getresources().getstringarray(r.array.failsafe_list));     faillistview.setadapter(adapter); 

any appreciated.

the following custom layout used in popup window (dialog.xml):

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="fill_parent"     android:layout_height="fill_parent" >       <linearlayout         android:id="@+id/headers_container"         android:layout_width="match_parent"         android:layout_height="30dp"         android:layout_margintop="5dp"         android:orientation="horizontal" >          <textview             android:id="@+id/textview1"             android:layout_width="100dp"             android:layout_height="wrap_content"             android:text="failsafe"             android:textsize="16sp" />          <textview             android:id="@+id/textview2"             android:layout_width="35dp"             android:layout_height="wrap_content"             android:layout_torightof="@+id/textview1"             android:text="on"             android:textsize="16sp" />      </linearlayout>        <listview         android:id="@android:id/list"         android:layout_width="wrap_content"         android:layout_height="350dp"         android:layout_alignparentleft="true"         android:layout_below="@+id/headers_container"         android:background="#ffeeaa" >     </listview>        <linearlayout         android:id="@+id/linearlayout1"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:gravity="center"         android:layout_below="@android:id/list"         android:orientation="horizontal" >          <button             android:id="@+id/dialogbuttonreset"             android:layout_width="100dp"             android:layout_height="wrap_content"             android:layout_marginright="5dp"             android:layout_margintop="5dp"             android:text="reset" />          <button             android:id="@+id/dialogbuttonsend"             android:layout_width="100dp"             android:layout_height="wrap_content"             android:layout_marginright="5dp"             android:layout_margintop="5dp"             android:text="send" />     </linearlayout>  </relativelayout> 

the following fragment has expandable list of drawable layout (settingsfragment.java):

public class settingsfragment extends fragment {   expandablelistadapter listadapter; expandablelistview explistview; list<string> listdataheader; hashmap<string, list<string>> listdatachild;  int position = 0; listview faillistview = null;   public settingsfragment() { }   @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {      // view rootview = inflater.inflate(r.layout.fragment_settings, container, false);     view rootview = inflater.inflate(r.layout.fragment_settings, null);             faillistview = (listview) rootview.findviewbyid(android.r.id.list);     testfailsafeadapter adapter = new testfailsafeadapter(getactivity().getapplicationcontext(),   r.layout.dialog,r.id.textview1, getresources().getstringarray(r.array.failsafe_list));   faillistview.setadapter(adapter);       return rootview; }    @override public void onactivitycreated(bundle savedinstancestate) {     // todo auto-generated method stub     super.onactivitycreated(savedinstancestate);       // listview     explistview = (expandablelistview) getactivity().findviewbyid(r.id.lvexp);      // preparing list data     preparelistdata();      listadapter = new expandablelistadapter(getactivity(), listdataheader, listdatachild);      // setting list adapter     explistview.setadapter(listadapter);      // listview group click listener     explistview.setongroupclicklistener(new ongroupclicklistener() {           public boolean ongroupclick(expandablelistview parent, view v,                 int groupposition, long id) {             return false;         }     });      // listview group expanded listener     explistview.setongroupexpandlistener(new ongroupexpandlistener() {          @override         public void ongroupexpand(int groupposition) {             toast.maketext(getactivity(),                     listdataheader.get(groupposition) + " expanded",                     toast.length_short).show();         }     });      // listview group collasped listener     explistview.setongroupcollapselistener(new ongroupcollapselistener() {          @override         public void ongroupcollapse(int groupposition) {             toast.maketext(getactivity(),                     listdataheader.get(groupposition) + " collapsed",                     toast.length_short).show();          }     });      // listview on child click listener     explistview.setonchildclicklistener(new onchildclicklistener() {          @override         public boolean onchildclick(expandablelistview parent, view v,                 final int groupposition, final int childposition, long id) {             // todo auto-generated method stub               if(listdatachild.get(listdataheader.get(groupposition)).get(childposition).equals("usb") ){                   fragmentmanager manager = getfragmentmanager();                  /** instantiating dialogfragment class */                 alertdialogradio alert = new alertdialogradio();                  /** creating bundle object store selected item's index */                 bundle b  = new bundle();                  /** storing selected item's index in bundle object */                 b.putint("position", position);                  /** setting bundle object dialog fragment object */                 alert.setarguments(b);                  /** creating dialog fragment object, in turn open alert dialog window */                 alert.show(manager, "alert_dialog_radio");              }                  if(listdatachild.get(listdataheader.get(groupposition)).get(childposition).equals("failsafe setup") ){                  toast.maketext(getactivity()," failsafe setup",toast.length_short).show();                   // create dialog component                 final dialog dialog = new dialog(getactivity());                  //tell dialog use dialog.xml it's layout description                 dialog.setcontentview(r.layout.dialog);                 dialog.settitle("failsafe setup");                   listview faillistview = (listview) dialog.findviewbyid(android.r.id.list);                 button dialogbuttonreset = (button) dialog.findviewbyid(r.id.dialogbuttonreset);                 button dialogbuttonsend = (button) dialog.findviewbyid(r.id.dialogbuttonsend);                   dialogbuttonreset.setonclicklistener(new onclicklistener() {                     @override                     public void onclick(view v) {                         toast.maketext(getactivity()," failsafe reset",toast.length_short).show();                      }                 });                  dialogbuttonsend.setonclicklistener(new onclicklistener() {                     @override                     public void onclick(view v) {                         toast.maketext(getactivity()," failsafe send",toast.length_short).show();                     }                 });                  dialog.show();              }              return false;         } // end of onclickchild method     });    }   private void preparelistdata() {     listdataheader = new arraylist<string>();      listdatachild = new hashmap<string, list<string>>();      // adding child data   listdataheader.add("connection");   listdataheader.add("mission limits");   listdataheader.add("compass calibration");   listdataheader.add("sensor calibration");   listdataheader.add("failsafe");   // adding child data   list<string> connection = new arraylist<string>();   connection.add("usb");   connection.add("wi-fi");     list<string> missionlimits = new arraylist<string>();   list<string> compasscalibration = new arraylist<string>();   list<string> sensorcalibration = new arraylist<string>();    list<string> failsafe = new arraylist<string>();   failsafe.add("failsafe setup");     listdatachild.put(listdataheader.get(0), connection); // header, child data   listdatachild.put(listdataheader.get(1), missionlimits);    listdatachild.put(listdataheader.get(2), compasscalibration);    listdatachild.put(listdataheader.get(3), sensorcalibration);    listdatachild.put(listdataheader.get(4), failsafe);   } 

}

npe here:

faillistview.setadapter(adapter); 

because listview android:id/list id inside dialog.xml layout dialog layout instead of in fragment_settings.xml settingsfragment fragment layout.

so, using context or object of dialog it's not possible access listview in oncreateview