# C1.DataCollection.C1DataCollectionList-1.OnCollectionChanged

## Content

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<h1 id="C1_DataCollection_C1DataCollectionList_1_OnCollectionChanged_" data-uid="C1.DataCollection.C1DataCollectionList`1.OnCollectionChanged*">OnCollectionChanged Method
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<div class="markdown level0 summary"></div>
<div class="markdown level0 conceptual"></div>



<a id="C1_DataCollection_C1DataCollectionList_1_OnCollectionChanged_" data-uid="C1.DataCollection.C1DataCollectionList`1.OnCollectionChanged*"></a>
<h4 id="C1_DataCollection_C1DataCollectionList_1_OnCollectionChanged_System_Collections_Specialized_NotifyCollectionChangedEventArgs_" data-uid="C1.DataCollection.C1DataCollectionList`1.OnCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs)">OnCollectionChanged(NotifyCollectionChangedEventArgs)</h4>
<div class="markdown level1 summary"><p>Raises the <span class="xref">CollectionChanged</span> event.</p>
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<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)</code></pre>
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  <pre><code class="lang-vbnet hljs">Protected Overridable Sub OnCollectionChanged(e As NotifyCollectionChangedEventArgs)</code></pre>
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<h5 class="parameters">Parameters</h5>
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      <th>Type</th>
      <th>Name</th>
      <th>Description</th>
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      <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><p>The <a class="xref" href="https://learn.microsoft.com/dotnet/api/system.collections.specialized.notifycollectionchangedeventargs">NotifyCollectionChangedEventArgs</a> instance containing the event data.</p>
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