android - Content view not yet created -

i trying retrieve data mysql , sort based on category tab. application crash when open activity content view not yet created. may know problem?

03-10 04:12:49.043: e/androidruntime(2251): fatal exception: main 03-10 04:12:49.043: e/androidruntime(2251): java.lang.runtimeexception: unable start activity componentinfo{my.fyp.inticlassifieds/my.fyp.inticlassifieds.displaypostitem}: java.lang.illegalstateexception: content view not yet created 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2211) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2261) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread.access$600(activitythread.java:141) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread$h.handlemessage(activitythread.java:1256) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.os.handler.dispatchmessage(handler.java:99) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.os.looper.loop(looper.java:137) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread.main(activitythread.java:5103) 03-10 04:12:49.043: e/androidruntime(2251):     @ java.lang.reflect.method.invokenative(native method) 03-10 04:12:49.043: e/androidruntime(2251):     @ java.lang.reflect.method.invoke(method.java:525) 03-10 04:12:49.043: e/androidruntime(2251):     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:737) 03-10 04:12:49.043: e/androidruntime(2251):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 03-10 04:12:49.043: e/androidruntime(2251):     @ dalvik.system.nativestart.main(native method) 03-10 04:12:49.043: e/androidruntime(2251): caused by: java.lang.illegalstateexception: content view not yet created 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.listfragment.ensurelist(listfragment.java:328) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.listfragment.getlistview(listfragment.java:222) 03-10 04:12:49.043: e/androidruntime(2251):     @ my.fyp.inticlassifieds.booksfragment.oncreateview(booksfragment.java:87) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.fragment.performcreateview(fragment.java:1500) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:927) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:1104) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.backstackrecord.run(backstackrecord.java:682) 03-10 04:12:49.043: e/androidruntime(2251):     @  android.support.v4.app.fragmentmanagerimpl.execpendingactions(fragmentmanager.java:1467) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.support.v4.app.fragmentactivity.onstart(fragmentactivity.java:570) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.instrumentation.callactivityonstart(instrumentation.java:1171) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activity.performstart(activity.java:5143) 03-10 04:12:49.043: e/androidruntime(2251):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 03-10 04:12:49.043: e/androidruntime(2251):     ... 11 more 

class:

public class booksfragment extends listfragment {  // progress dialog private progressdialog pdialog;  // creating json parser object jsonparser jparser = new jsonparser(); jsonobject json;  arraylist<products> productslist = new arraylist<products>();  // url products list private static string url_all_products = "http://10.0.2.2:8000/project/display_items.php";  // json node names private static final string tag_success = "success"; private static final string tag_products = "product"; private static final string tag_pid = "pid"; private static final string tag_name = "name"; private static final string tag_budget = "price"; private static final string tag_des = "description"; private static final string tag_date_posted = "created_at"; private static final string tag_category = "category"; private static final string tag_email = "email"; private static final string tag_contact = "contact";  // products jsonarray jsonarray products = null;  listview lv; listadapter listadapter;   @override public view oncreateview(layoutinflater inflater, viewgroup container,         bundle savedinstancestate) {     view rootview = inflater.inflate(r.layout.list_fragment, container,             false);      productslist = new arraylist<products>();      lv = getlistview();      // on seleting single product     // launching edit product screen     lv.setonitemclicklistener(new onitemclicklistener() {          @override         public void onitemclick(adapterview<?> parent, view view,                 int position, long id) {             // getting values selected listitem             string pid = ((textview) view.findviewbyid(r.id.pid)).gettext()                     .tostring();             string name = ((textview) view.findviewbyid(r.id.name))                     .gettext().tostring();             string description = ((textview) view.findviewbyid(r.id.des))                     .gettext().tostring();             string price = ((textview) view.findviewbyid(r.id.budget))                     .gettext().tostring();             string date = ((textview) view.findviewbyid(r.id.date_posted))                     .gettext().tostring();             string category = ((textview) view.findviewbyid(r.id.category))                     .gettext().tostring();             string email = ((textview) view                     .findviewbyid(r.id.email_request)).gettext().tostring();             string contact = ((textview) view                     .findviewbyid(r.id.contact_request)).gettext()                     .tostring();              // starting new intent             intent in = new intent(getactivity(), displayiteminfo.class);             // sending information next activity             in.putextra(tag_pid, pid);             in.putextra(tag_name, name);             in.putextra(tag_des, description);             in.putextra(tag_budget, price);             in.putextra(tag_date_posted, date);             in.putextra(tag_category, category);             in.putextra(tag_email, email);             in.putextra(tag_contact, contact);             startactivity(in);         }     });      new loadallproducts().execute();     return rootview; }   class loadallproducts extends asynctask<string, string, string> {      /**      * before starting background thread show progress dialog      * */     @override     protected void onpreexecute() {         super.onpreexecute();         pdialog = new progressdialog(getactivity());         pdialog.setmessage("loading products. please wait...");         pdialog.setindeterminate(false);         pdialog.setcancelable(false);         pdialog.show();     }      /**      * getting products url      * */     protected string doinbackground(string... args) {         // building parameters         list<namevaluepair> params = new arraylist<namevaluepair>();         intent intent = getintent();         // getting attached intent data         string jsons = intent.getstringextra("json");          if (jsons == null) {             // getting json string url             json = jparser.makehttprequest(url_all_products, "get", params);         } else {             try {                 jsonobject jsonobj = new jsonobject(jsons);                 json = jsonobj;             } catch (jsonexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             }         }          // check log cat json reponse         log.d("all products: ", json.tostring());          try {             // checking success tag             int success = json.getint(tag_success);              if (success == 1) {                 // products found                 // getting array of products                 products = json.getjsonarray(tag_products);                  // looping through products                 (int = 0; < products.length(); i++) {                     jsonobject c = products.getjsonobject(i);                      // storing each json item in variable                     string id = c.getstring(tag_pid);                     string name = c.getstring(tag_name);                     string budget = c.getstring(tag_budget);                     string description = c.getstring(tag_des);                     string category = c.getstring(tag_category);                     string contact = c.getstring(tag_contact);                     string email = c.getstring(tag_email);                     string date = c.getstring(tag_date_posted);                      if (category == "books") {                          // create new product obect, set values                         products mproduct = new products();                         mproduct.pid = id;                         mproduct.name = name;                         mproduct.price = budget;                         mproduct.description = description;                         mproduct.date = date;                         mproduct.category = category;                         mproduct.email = email;                         mproduct.contact = contact;                          // adding product arraylist                         productslist.add(mproduct);                     }                 }             } else {                 // no products found                 // launch add new product activity                 intent = new intent(getactivity(), mainmenu.class);                 // closing previous activities                 i.addflags(intent.flag_activity_clear_top);                 startactivity(i);             }         } catch (jsonexception e) {             e.printstacktrace();         }          return null;     }      private intent getintent() {         // todo auto-generated method stub         return null;     }      /**      * after completing background task dismiss progress dialog      * **/      protected void onpostexecute(string file_url) {         // dismiss dialog after getting products         pdialog.dismiss();          if (productslist.size() > 0) {             /**              * updating parsed json data listview              * */             customadapter adapter = new customadapter(getactivity(),                     productslist);// ,              if (getlistview() != null) {                  // updating listview                 setlistadapter(adapter);             } else {                 log.d("listview-reference", "listview null");             }         } else {             log.d("product list", "products list empty");         }     } } } 

oncreateview must return view represent fragment. other operations on view should performed in callback, onviewcreated:

  @override  public view oncreateview(layoutinflater inflater, viewgroup container,             bundle savedinstancestate) {              return inflater.inflate(r.layout.list_fragment, container, false);  }   @override   public void onviewcreated (view view, bundle savedinstancestate) {        productslist = new arraylist<products>();  lv = getlistview();  // on seleting single product // launching edit product screen lv.setonitemclicklistener(new onitemclicklistener() {      @override     public void onitemclick(adapterview<?> parent, view view,             int position, long id) {         // getting values selected listitem         string pid = ((textview) view.findviewbyid(r.id.pid)).gettext()                 .tostring();         string name = ((textview) view.findviewbyid(r.id.name))                 .gettext().tostring();         string description = ((textview) view.findviewbyid(r.id.des))                 .gettext().tostring();         string price = ((textview) view.findviewbyid(r.id.budget))                 .gettext().tostring();         string date = ((textview) view.findviewbyid(r.id.date_posted))                 .gettext().tostring();         string category = ((textview) view.findviewbyid(r.id.category))                 .gettext().tostring();         string email = ((textview) view                 .findviewbyid(r.id.email_request)).gettext().tostring();         string contact = ((textview) view                 .findviewbyid(r.id.contact_request)).gettext()                 .tostring();          // starting new intent         intent in = new intent(getactivity(), displayiteminfo.class);         // sending information next activity         in.putextra(tag_pid, pid);         in.putextra(tag_name, name);         in.putextra(tag_des, description);         in.putextra(tag_budget, price);         in.putextra(tag_date_posted, date);         in.putextra(tag_category, category);         in.putextra(tag_email, email);         in.putextra(tag_contact, contact);         startactivity(in);     } });  new loadallproducts().execute();  }