title: Xamarin.Forms NotifyPropertyChanged does not update already existing items (Android)
body: <p>I have a ListView like this:</p>
  <pre class="lang-xml prettyprint-override"><code>        &lt;ListView x:Name=&quot;ItemsListView&quot;
                  ItemsSource=&quot;{Binding Items}&quot;
                  VerticalOptions=&quot;FillAndExpand&quot;
                  HasUnevenRows=&quot;true&quot;
                  RefreshCommand=&quot;{Binding LoadItemsCommand}&quot;
                  IsPullToRefreshEnabled=&quot;False&quot;
                  IsRefreshing=&quot;{Binding IsBusy, Mode=OneWay}&quot;
                  CachingStrategy=&quot;RecycleElement&quot;
                  ItemSelected=&quot;OnItemSelected&quot;&gt;
  </code></pre>
  <p>and my ViewModel has this definitions and my Model class looks like this:</p>
  <pre class="lang-cs prettyprint-override"><code>    public ObservableCollection&lt;IncomingJobItem&gt; Items { get; set; }
  </code></pre>
  <pre class="lang-cs prettyprint-override"><code>    public class IncomingJobItem
      {
          public int Index { get; set; }
  
          [JsonProperty(&quot;id&quot;)]
          public string Id { get; set; }
  
          [JsonProperty(&quot;name&quot;)]
          public string Name { get; set; }
  
          [JsonProperty(&quot;amount&quot;)]
          public int Amount { get; set; }
      }
  </code></pre>
  <p>Now when I update <code>ViewModelObject.Items</code> and call <code>NotifyPropertyChanged</code> the already existing items in the ListView do not get updated.</p>
  <p>Example:</p>
  <pre class="lang-cs prettyprint-override"><code>// change already existing item
  ViewModelObject.Items[0].Amount = 3;
  
  // notify item in Items has changed
  ViewModelObject.NotifyPropertyChanged(&quot;Items&quot;);
  
  // nothing happens, item 0 in the list stays with the old amount...
  // expected is to update the item in the list to display 3
  </code></pre>
  <p>But when I create and add a new element to <code>ViewModelObject.Items</code>, the ListView adds the new Item but does not update the already existing item. What can I do?</p>
  <p>Also <code>ViewModelObject.NotifyPropertyChanged(&quot;Items.Amount&quot;);</code> does nothing.</p>