android - need help to fix code for getting current view in viewpager -

need fix code saw in https://stackoverflow.com/a/9275732/1938357. solution need current view onany page in viewpager based application

below code reference

public view getcurrentview(viewpager pager) { (int = 0; < pager.getchildcount(); i++) {     view child = pager.getchildat(i);     if (child.getx() <= pager.getscrollx() + pager.getwidth()          && child.getx() + child.getwidth() >= pager.getscrollx() + pager.getwidth()) {         return child;      }   } return getchildat(0); 

i trying access current view in view pager , used code above. works fine when scroll forwards. when scroll backwards after 2 backward scrolls stops working.

public class myactivity extends fragmentactivity //variable declarations protected void oncreate(bundle savedinstancestate) { viewpager mpager = (viewpager) findviewbyid(r.id.pager); mpageradapter = new screenslidepageradapter(getsupportfragmentmanager()); mpager.setadapter(mpageradapter); view currview;  onpagechangelistener pagechangelistener = new onpagechangelistener() {   @override   public void onpageselected(int pageselected) {     dotextviewchnges();//access text view , update based on pageselected     ---this stuck in trying textview in current fragmwnt/view-------  }  mpager.setonpagechangelistener(pagechangelistener); } private class screenslidepageradapter extends fragmentstatepageradapter {    public screenslidepageradapter(android.support.v4.app.fragmentmanager  fm) {     super(fm);  }   @override  public android.support.v4.app.fragment getitem(int position) {      return screenslidepagefragment.create(position, <other parameters want pass>);  }   @override  public int getcount() {     return num_pages;  } }   

and below screenslidepagefragment class

public class screenslidepagefragment extends android.support.v4.app.fragment {  public static final string arg_page = "pagenumber"; public static final string arg_pagearray = "pages";  private int mpagenumber; //declare other variables  @suppresslint("newapi") public static screenslidepagefragment create(int pagenumber, string[] pages, int bookmarkpagenumber, string storyname, int linesinonepage) {     screenslidepagefragment fragment = new screenslidepagefragment();     bundle args = new bundle();     args.putint(arg_page, pagenumber);     args.putstringarray(arg_pagearray, pages);     fragment.setarguments(args);      return fragment; }  @suppresslint("newapi") public screenslidepagefragment() { }  @suppresslint("newapi") @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     mpagenumber = getarguments().getint(arg_page);     pages = getarguments().getstringarray(arg_pagearray); }  @override public view oncreateview(layoutinflater inflater, viewgroup container,         bundle savedinstancestate) {     rootview = (viewgroup) inflater             .inflate(r.layout.activity_story, container, false);      //load layout components filled page     loadview(rootview);     return rootview; } public int getpagenumber() {     return mpagenumber; } 

it hard discuss in comments example of code.

as see in grepcode fragmentstatepageradapter.setprimaryitem(), receive object android.support.v4.app.fragment. receive classcastexception when trying cast object fragment. can check casting: cast object in android.support.v4.app.fragment not in android.app.fragment? if right, add exception message question, please.

update:

if screenslidepageradapter has method getcurrentview(), method 'getcurrentview()' can work this:

public view getcurrentview(viewpager pager) {     return ((screenslidepageradapter) pager.getadapter()).getcurrentview(); } 

and method getcurrentview() of screenslidepageradapter:

public view getcurrentview() {     return currview; } 

update 2:

i've made modification code:

your activity private adapter:

public class myactivity extends fragmentactivity implements iselectitemlistener {     // variable declarations , methods      @override     protected void oncreate(bundle savedinstancestate) {         final viewpager pager = (viewpager) findviewbyid(r.id.pager);          mpageradapter = new screenslidepageradapter(getsupportfragmentmanager());         pager.setadapter(mpageradapter);          pager.setonpagechangelistener(                 new onpagechangelistener() {                     @override                     public void onpageselected(int pageselected) {                         final screenslidepagefragment fragment = mpageradapter.getfragment(pageselected);                          if (fragment != null) {                             fragment.dotextviewchnges();                         }                     }                      @override                     public void onpagescrollstatechanged(int arg0) {                         // todo auto-generated method stub                     }                      @override                     public void onpagescrolled(int arg0, float arg1, int arg2) {                         // todo auto-generated method stub                     }                 });     }      private class screenslidepageradapter extends fragmentstatepageradapter {         //your variable declarations          private final screenslidepagefragment[] mfragments;          public screenslidepageradapter(android.support.v4.app.fragmentmanager fm) {             super(fm);              mfragments = new screenslidepagefragment[num_pages];         }          @override         public int getcount() {             return num_pages;         }             // create new screenslidepagefragment position if it's not exsist         @override         public android.support.v4.app.fragment getitem(int position) {             if (getfragment(position) == null) {                 mfragments[position] = screenslidepagefragment.create(position, <other parameters want pass>);             }              return getfragment(position);         }          // give screenslidepagefragment if it's exists, or null         public screenslidepagefragment getfragment(int position) {             return mfragments[position];         }     } } 

your fragment:

public class screenslidepagefragment extends fragment {     //your variables , methods      public static screenslidepagefragment create(int pagenumber, string[] pages, int bookmarkpagenumber, string storyname, int linesinonepage) {         final bundle args = new bundle();         args.putint(arg_page, pagenumber);         args.putstringarray(arg_pagearray, pages);          final screenslidepagefragment fragment = new screenslidepagefragment();         fragment.setarguments(args);           return fragment;     }      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         mpagenumber = getarguments().getint(arg_page);         pages = getarguments().getstringarray(arg_pagearray);     }      @override     public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {         rootview = (viewgroup) inflater.inflate(r.layout.activity_story, container, false);          loadview(rootview);         return rootview;     }      public int getpagenumber() {         return mpagenumber;     }      // let's keep logic of modifications in fragment     public void dotextviewchnges() {         final view view = getview();         // want view , children     } }