# C1.DataCollection.C1HierarchicalDataCollection-1.OnInternalCollectionsChangedAsync

## Content

<div class="doc-site-dotnet-api-container">



<h1 id="C1_DataCollection_C1HierarchicalDataCollection_1_OnInternalCollectionsChangedAsync_" data-uid="C1.DataCollection.C1HierarchicalDataCollection`1.OnInternalCollectionsChangedAsync*">OnInternalCollectionsChangedAsync Method
</h1>
<div class="markdown level0 summary"></div>
<div class="markdown level0 conceptual"></div>



<a id="C1_DataCollection_C1HierarchicalDataCollection_1_OnInternalCollectionsChangedAsync_" data-uid="C1.DataCollection.C1HierarchicalDataCollection`1.OnInternalCollectionsChangedAsync*"></a>
<h4 id="C1_DataCollection_C1HierarchicalDataCollection_1_OnInternalCollectionsChangedAsync_System_Object_System_Collections_Specialized_NotifyCollectionChangedEventArgs_" data-uid="C1.DataCollection.C1HierarchicalDataCollection`1.OnInternalCollectionsChangedAsync(System.Object,System.Collections.Specialized.NotifyCollectionChangedEventArgs)">OnInternalCollectionsChangedAsync(object?, NotifyCollectionChangedEventArgs)</h4>
<div class="markdown level1 summary"><p>Called when the InternalCollections changed.</p>
</div>
<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
<div class="codewrapper">
  <pre><code class="lang-csharp hljs">protected virtual Task OnInternalCollectionsChangedAsync(object? sender, NotifyCollectionChangedEventArgs e)</code></pre>
</div>
<div class="codewrapper">
  <pre><code class="lang-vbnet hljs">Protected Overridable Function OnInternalCollectionsChangedAsync(sender As Object, e As NotifyCollectionChangedEventArgs) As Task</code></pre>
</div>
<h5 class="parameters">Parameters</h5>
<table class="table table-bordered table-condensed">
  <thead>
    <tr>
      <th>Type</th>
      <th>Name</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.object">object</a></td>
      <td><span class="parametername">sender</span></td>
      <td></td>
    </tr>
    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.collections.specialized.notifycollectionchangedeventargs">NotifyCollectionChangedEventArgs</a></td>
      <td><span class="parametername">e</span></td>
      <td></td>
    </tr>
  </tbody>
</table>
<h5 class="returns">Returns</h5>
<table class="table table-bordered table-condensed">
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.threading.tasks.task">Task</a></td>
      <td></td>
    </tr>
  </tbody>
</table>
</div>