java - NullPointerException in NavDrawerListAdapter for NavigationDrawer in Android -

i having strange problem. using navdrawerlistadapter navigationdrawer in android app. if list has 13 items (navdraweritem), works ok. however, when add 14th element, app appears crash , give nullpointerexception. checked resources,strings,etc , appears correct. stacktrace pointing @ class inside getview() on following line:

imgicon.setimageresource(navdraweritems.get(position).geticon());

for reason, imgicon null.

public class navdrawerlistadapter extends baseadapter {     private static final string tag = "navdrawerlistadapter";     private context context;     private arraylist<navdraweritem> navdraweritems;     private list<boolean> enableddraweritems;     private layoutinflater minflater;      public navdrawerlistadapter(context context,             arraylist<navdraweritem> navdraweritems)      {         super();         this.context = context;         this.navdraweritems = navdraweritems;         this.minflater = (layoutinflater) context.getsystemservice(activity.layout_inflater_service);          // toggle enabled/disabled navigation drawer items         enableddraweritems = new arraylist<boolean>(arrays.aslist(new boolean[navdraweritems.size()]));         collections.fill(enableddraweritems, new boolean(true));     }      @override     public int getcount() {         return navdraweritems.size();     }      @override     public object getitem(int position) {         return navdraweritems.get(position);     }      @override     public long getitemid(int position) {         return position;     }      @override     public view getview(int position, view convertview, viewgroup parent)   {         if(position == 0)       {             convertview = minflater.inflate(r.layout.header_view, null);             return convertview;         }          if(convertview == null)     {             // use drawer list item view             convertview = minflater.inflate(r.layout.drawer_list_item, null);         }          imageview imgicon = (imageview) convertview.findviewbyid(r.id.icon);         textview txttitle = (textview) convertview.findviewbyid(r.id.title);         textview txtcounter = (textview) convertview.findviewbyid(r.id.counter);          log.d(tag, "position: " + position + ", icon resource: " + navdraweritems.get(position).geticon());         log.d(tag, "navdraweritems: " + navdraweritems.size());         if(imgicon == null){             log.d(tag, "imgicon null");         }         else{             log.d(tag, "imgicon not null");         }          imgicon.setimageresource(navdraweritems.get(position).geticon());         txttitle.settext(navdraweritems.get(position).gettitle());          if(navdraweritems.get(position).iscountervisible()){             txtcounter.settext(navdraweritems.get(position).getcount());         }         else{             txtcounter.setvisibility(view.gone);         }          if(enableddraweritems.get(position) == false)       {             txttitle.settextcolor(color.ltgray);             convertview.setenabled(enableddraweritems.get(position));         }         return convertview;     }      @override     public boolean areallitemsenabled()     {         return false;     }      @override     public boolean isenabled(int position)  {         return enableddraweritems.get(position);     }      // set state of navigation drawer item     public void setnavigationdraweritem(int pos, boolean enabled)   {         enableddraweritems.set(pos, enabled);     } } 

strings.xml

<array name="nav_drawer_icons">         <item>@drawable/ic_home</item>         <item>@drawable/ic_people</item>         <item>@drawable/ic_photos</item>         <item>@drawable/ic_communities</item>         <item>@drawable/ic_pages</item>         <item>@drawable/ic_whats_hot</item>     </array> 

navigationdraweractivity

public class navigationdraweractivity extends actionbaractivity {     public drawerlayout mdrawerlayout;     public listview mdrawerlist;     private actionbardrawertoggle mdrawertoggle;      public charsequence mdrawertitle; // nav drawer title     public charsequence mtitle; // store app title      public typedarray navmenuicons; // menu item icons     public string[] navmenutitles; // menu item titles      public arraylist<navdraweritem> navdraweritems; // each drawer item     public navdrawerlistadapter adapter; // nav drawer adapter      // static settings/configuration     private static final int navigation_drawer_width_percent = 85; // in percentage     private static final string tag = "mainactivity";     public static final string intent_extra_position = "navigationdrawerposition";      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          // use toolbar , set actionbar         toolbar toolbar = (toolbar) findviewbyid(r.id.my_awesome_toolbar);          setsupportactionbar(toolbar);          // nav menu icons , titles         navmenuicons = getresources().obtaintypedarray(r.array.nav_drawer_icons);         navmenutitles = getresources().getstringarray(r.array.nav_drawer_items);          // drawerlayout , listview         mdrawerlayout = (drawerlayout) findviewbyid(r.id.drawer_layout);         mdrawerlist = (listview) findviewbyid(r.id.list_slidermenu);          navdraweritems = new arraylist<navdraweritem>();          addnavdraweritems(); // add each navigation drawer item          // recycle array         navmenuicons.recycle();          // setup nav drawer list adapter         adapter = new navdrawerlistadapter(this.getapplicationcontext(), navdraweritems);          mdrawerlist.setadapter(adapter);         mdrawerlist.setonitemclicklistener(new slidemenuclicklistener());          // enabling action bar app icon , behaving toggle button         getsupportactionbar().setdisplayhomeasupenabled(true);         getsupportactionbar().sethomebuttonenabled(true);          mdrawertoggle = new actionbardrawertoggle(this,                                                   mdrawerlayout, //                                                r.drawable.ic_drawer,                                                   r.string.app_name,                                                   r.string.app_name)         {             public void ondrawerclosed(view view){                 getsupportactionbar().settitle(mtitle);                 invalidateoptionsmenu();             }              public void ondraweropened(view drawerview){                 getsupportactionbar().settitle(mtitle);                 invalidateoptionsmenu();             }         };          mdrawerlayout.setdrawerlistener(mdrawertoggle);          intent intent = getintent();         if(intent != null && intent.getextras() != null) {             int drawerposition = intent.getextras().getint(intent_extra_position);             if(drawerposition != 0) {                 // update selected item, title, , close drawer                 mdrawerlist.setitemchecked(drawerposition, true);                 mdrawerlist.setselection(drawerposition);                 settitle(navmenutitles[drawerposition-1]);             }             else {                 log.w(tag, "drawerposition 0");             }         }          mdrawertitle = gettitle();         mtitle = mdrawertitle;          configurenavigationdrawer();         configureenableddisablednavdrawitems();     }      private void configureenableddisablednavdrawitems() {         // check if device connected (no: disable list item, yes: enable list item)         if(secondscreeniab.getinstance().getdevice() == null)         {             getadapter().setnavigationdraweritem(2, false);              getadapter().setnavigationdraweritem(3, false);          }         else         {             getadapter().setnavigationdraweritem(2, true);              getadapter().setnavigationdraweritem(3, true);          }     }      private void addnavdraweritems() {         navdraweritems.add(new navdraweritem(0, "")); // drawer cover image         navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(0, -1), navmenutitles[0]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(1, -1), navmenutitles[1]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(2, -1), navmenutitles[2]));                       navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(3, -1), navmenutitles[3]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(4, -1), navmenutitles[4], "23", false));         navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(5, -1), navmenutitles[5]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(0, -1), navmenutitles[6], "5", false));           navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(1, -1), navmenutitles[7]));                       navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(2, -1), navmenutitles[8]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(3, -1), navmenutitles[9]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(4, -1), navmenutitles[10]));                     navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(5, -1), navmenutitles[11]));                     navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(0, -1), navmenutitles[12]));                      navdraweritems.add(new navdraweritem(navmenuicons.getresourceid(1, -1), navmenutitles[13]));                 }      public void configureactionbar()    {         spannablestring s = new spannablestring("test");         s.setspan(new typefacespan(this, "roboto-regular.ttf"), 0, s.length(),                 spannable.span_exclusive_exclusive);          // update action bar title typefacespan instance         android.support.v7.app.actionbar actionbar = this.getsupportactionbar();         actionbar.settitle(s);     }      private void configurenavigationdrawer()    {         // configure navigation drawer width         drawerlayout.layoutparams params = (android.support.v4.widget.drawerlayout.layoutparams) mdrawerlist.getlayoutparams();         params.width = (int) (getresources().getdisplaymetrics().widthpixels * (navigation_drawer_width_percent/100.0));         mdrawerlist.setlayoutparams(params);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         getmenuinflater().inflate(r.menu.main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         if(mdrawertoggle.onoptionsitemselected(item)){             return true;         }          int id = item.getitemid();         if (id == r.id.action_settings) {             return true;         }         return super.onoptionsitemselected(item);     }      @override     public boolean onprepareoptionsmenu(menu menu){         boolean draweropen = mdrawerlayout.isdraweropen(mdrawerlist);         menu.finditem(r.id.action_settings).setvisible(!draweropen);         return super.onprepareoptionsmenu(menu);     }      @override     public void settitle(charsequence title) {         mtitle = title;         getsupportactionbar().settitle(mtitle);     }      @override     protected void onpostcreate(bundle savedinstancestate) {         super.onpostcreate(savedinstancestate);         mdrawertoggle.syncstate();     }      @override     public void onconfigurationchanged(configuration newconfig) {         super.onconfigurationchanged(newconfig);         mdrawertoggle.onconfigurationchanged(newconfig);     }     public listview getmdrawerlist() {         return mdrawerlist;     }      public void setmdrawerlist(listview mdrawerlist) {         this.mdrawerlist = mdrawerlist;     }      public navdrawerlistadapter getadapter() {         return adapter;     }      public void setadapter(navdrawerlistadapter adapter) {         this.adapter = adapter;     } } 

you seem using 2 different layouts:

• r.layout.header_view
• r.layout.drawer_list_item

i'm guessing "r.layout.header_view" doesn't have "r.id.icon". when tries reuse it, imgicon null.

base adapter has methods

public int getitemviewtype (int position) public int getviewtypecount () 

you have 2 types of views. need make sure item @ position 0 has different type rest.

you need add these 2 methods adapter:

@override public int getitemviewtype (int position) {     if(position == 0)         return 0;     else         return 1; }  @override public int getviewtypecount () {     return 2; } 

and update first if statement in getview to:

    if(position == 0) {         if(convertview == null)              convertview = minflater.inflate(r.layout.header_view, null);         return convertview;     }