android - ExpandableListView; When I click on first group's switchCompat, other group's switchCompat click on and vise versa -

i created expandablelistview have had many errors. "flat list position of unknown type". don't error when click on group's switchcompact child, other group's switchcompact child clicked. adapter below:

public class expandablelistadapter extends baseexpandablelistadapter {     private string company_name_array[] = { "po" ,  "opet" ,  "shell" ,  "bp" };     private int company_icon_array[] = { r.drawable.po,             r.drawable.opet, r.drawable.shell,             r.drawable.bp };      static public list<string> stationlist;     static public list<string> fuellist;     static public boolean density;     private imageview image1;     private imageview image2;     private textview text1;     private textview text2;     private context _context;     private list<string> _listdataheader; // header titles     // child data in format of header title, child title     private hashmap<string, list<string>> _listdatachild;      public expandablelistadapter(context context, list<string> listdataheader,                                  hashmap<string, list<string>> listchilddata) {         this._context = context;         this._listdataheader = listdataheader;         this._listdatachild = listchilddata;         stationlist = new arraylist<>();         fuellist = new arraylist<>();         density = false;     }      public expandablelistadapter()     {      }     @override     public object getchild(int groupposition, int childposititon) {         return this._listdatachild.get(this._listdataheader.get(groupposition))                 .get(childposititon);     }      @override     public long getchildid(int groupposition, int childposition) {         return childposition;     }      @override     public view getchildview(int groupposition, final int childposition,                              boolean islastchild, view convertview, viewgroup parent) {          final string childtext = (string) getchild(groupposition, childposition);         viewholder holder;          if (convertview == null) {             layoutinflater infalinflater = (layoutinflater) this._context                     .getsystemservice(context.layout_inflater_service);             convertview = infalinflater.inflate(r.layout.list_item2, null);             /*holder = new viewholder();             holder.toogle = (switchcompat) convertview.findviewbyid(r.id.switch2);             holder.toogle.settext(childtext);*/         }         /*else         {             holder = new viewholder();             holder.toogle = (switchcompat) convertview.findviewbyid(r.id.switch2);             holder.toogle.settext(childtext);         }         holder.toogle.settext(childtext);*/          switchcompat toogle = (switchcompat) convertview.findviewbyid(r.id.switch2);         toogle.settext(childtext);         if(groupposition == 0)         {             /*imageview image = (imageview) convertview.findviewbyid(r.id.company_icon);             typedarray img = this._context.getresources().obtaintypedarray(r.array.company_icon);              for(int = 0; < company_name_array.length; i++)             {                 if(company_name_array[i].contains(childtext) && childtext.contains(company_name_array[i]))                 {                     image.setbackgroundresource(img.getresourceid(i, -1));                     break;                 }             }*/             clicktoogle(toogle);         }         else if(groupposition == 1)//il         {          }         else if(groupposition == 2)//akaryakıt         {             clicktooglefuel(toogle);          }         else if(groupposition == 3)//yoğunluk         {             clicktoogledensity(toogle);         }          //txtlistchild.settext(childtext);         return convertview;     }      @override     public int getchildrencount(int groupposition) {         return this._listdatachild.get(this._listdataheader.get(groupposition))                 .size();     }      public static class viewholder {         public switchcompat toogle;     }      @override     public object getgroup(int groupposition) {         return this._listdataheader.get(groupposition);     }      @override     public int getgroupcount() {         return this._listdataheader.size();     }      @override     public long getgroupid(int groupposition) {         return groupposition;     }      @override     public view getgroupview(int groupposition, boolean isexpanded,                              view convertview, viewgroup parent) {         string headertitle = (string) getgroup(groupposition);         if (convertview == null) {             layoutinflater infalinflater = (layoutinflater) this._context                     .getsystemservice(context.layout_inflater_service);             convertview = infalinflater.inflate(r.layout.list_group, null);         }          textview lbllistheader = (textview) convertview                 .findviewbyid(r.id.lbllistheader);         lbllistheader.settypeface(null, typeface.bold);         lbllistheader.settext(headertitle);          return convertview;     }      @override     public boolean hasstableids() {         return false;     }      @override     public boolean ischildselectable(int groupposition, int childposition) {         return true;     }      public list<string> getarraylist()     {         return stationlist;     }  }