c# - ListView not updating when the bound ObservableCollection changes -

i'm working on search window loads search results observablecollection , displays results using listview.

setting listview's itemsource observablecollection after search complete populates list correctly.

i'm trying listview update search adds additional results, listview doesn't populate data @ all. can't work out binding falling over.

my research showed various ways of using datacontext, though none seem help; i've tried assigning "this" , cacheddata class using codebehind @ xaml window level.

sorry long code snippets, i've left think may add context question.

xaml:

<window x:class="slx_interface.mainwindow"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"     xmlns:local="clr-namespace:slx_interface"     mc:ignorable="d"     title="slx search" height="auto" width="auto"> <window.commandbindings> </window.commandbindings> <grid>     <grid.resources>         <local:cacheddata x:key="cacheddata" />     </grid.resources>     <tabcontrol x:name="tabcontrol" grid.rowspan="2" margin="0,20,0,0">         <tabitem header="accounts" name="accountstab">             <grid>                 <listview x:name="accountsearchresultslistview" margin="5,32,5,30" datacontext="staticresource cacheddata" itemssource="{binding path=accounts}" issynchronizedwithcurrentitem="true">                     <listview.view>                         <gridview x:name="accountsearchresultsgridview">                             <gridviewcolumn header="sdata key" displaymemberbinding="{binding sdatakey}"/>                             <gridviewcolumn header="account name" displaymemberbinding="{binding accountname}"/>                         </gridview>                     </listview.view>                 </listview>              </grid>         </tabitem>     </tabcontrol> </grid> 

code-behind within mainwindow.xaml.cs:

private async void searchaccount(string searchterm, string searchfield, string searchoperator)     {         //create string we'll use searching         string urlstring = "stuff";          //create observablecollection, use blank cache         observablecollection<account> resultslist = new observablecollection<account>();         cacheddata.accounts = resultslist;          //getting data search using xml reader         xmlreader resultsreader = null;          try         {             //using xmlreader grab search results slx             xmlurlresolver resultsresolver = new xmlurlresolver();             resultsresolver.credentials = logincredentials.usercred;              xmlreadersettings resultsreadersettings = new xmlreadersettings();             resultsreadersettings.xmlresolver = resultsresolver;             resultsreadersettings.async = true;              resultsreader = xmlreader.create(urlstring, resultsreadersettings);         }         catch (exception error)         {          }          //grabbing data xml , storing it, updating listview go         using (resultsreader)         {             while (await resultsreader.readasync())             {                 while (resultsreader.readtofollowing("slx:account"))                 {                     //setting data xml new account object ready passed list                     account account = new account();                     account.guid = new guid();                      resultsreader.movetofirstattribute(); account.sdatakey = resultsreader.value;                     resultsreader.readtofollowing("slx:accountname"); account.accountname = resultsreader.readelementcontentasstring();                      cacheddata.accounts.add(account);                      //--uncommenting gives odd results;                     //--the first item displayed, others aren't.                     //--if there lot of items, application errors mad , ends.                     //--looks 1 error window each item, though don't see message before die along application.                     //accountsearchresultslistview.itemssource = cacheddata.accounts;                 }             }         }          //--uncommenting works shows data once entire xml has been read through, can take time isn't ideal.         //accountsearchresultslistview.itemssource = cacheddata.accounts;        } 

classes references above, stored in separate .cs file under same namespace:

public class cacheddata {     public static observablecollection<account> accounts { get; set; }      public static event propertychangedeventhandler propertychanged;      public static event eventhandler<propertychangedeventargs> staticpropertychanged = delegate { };     private static void notifystaticpropertychanged(string propertyname)     {         staticpropertychanged(null, new propertychangedeventargs(propertyname));     } }  public class account : iequatable<account> {     public guid guid { get; set; }     public string sdatakey { get; set; }     public string accountname { get; set; }      public override string tostring()     {         return accountname;     }      public override bool equals(object obj)     {         if (obj == null) return false;         account objaspart = obj account;         if (objaspart == null) return false;         else return equals(objaspart);     }      public override int gethashcode()     {         return 0;     }      public bool equals(account other)     {         if (other == null) return false;         return (guid.equals(other.guid));     } } 

i appreciate can offer, has stumped me days now.

when set data binding in xaml, instance of observablecollection exists when app starts bound. instantiate instance before app starts , not replace new instance unless reset data binding in code behind. if need clear elements, use clear method.