# C1.Blazor.TreeView.C1TreeView.C1TreeViewReference.OnCollapseAsync

## Content

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<h1 id="C1_Blazor_TreeView_C1TreeView_C1TreeViewReference_OnCollapseAsync_" data-uid="C1.Blazor.TreeView.C1TreeView.C1TreeViewReference.OnCollapseAsync*">OnCollapseAsync Method
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<a id="C1_Blazor_TreeView_C1TreeView_C1TreeViewReference_OnCollapseAsync_" data-uid="C1.Blazor.TreeView.C1TreeView.C1TreeViewReference.OnCollapseAsync*"></a>
<h4 id="C1_Blazor_TreeView_C1TreeView_C1TreeViewReference_OnCollapseAsync_System_String_System_String_" data-uid="C1.Blazor.TreeView.C1TreeView.C1TreeViewReference.OnCollapseAsync(System.String,System.String)">OnCollapseAsync(string, string)</h4>
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<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">[JSInvokable]
public Task&lt;bool&gt; OnCollapseAsync(string targetDragId, string targetDragTreeId)</code></pre>
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  <pre><code class="lang-vbnet hljs">&lt;JSInvokable&gt;
Public Function OnCollapseAsync(targetDragId As String, targetDragTreeId As String) As Task(Of Boolean)</code></pre>
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<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.string">string</a></td>
      <td><span class="parametername">targetDragId</span></td>
      <td></td>
    </tr>
    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.string">string</a></td>
      <td><span class="parametername">targetDragTreeId</span></td>
      <td></td>
    </tr>
  </tbody>
</table>
<h5 class="returns">Returns</h5>
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  <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-1">Task</a>&lt;<a class="xref" href="https://learn.microsoft.com/dotnet/api/system.boolean">bool</a>&gt;</td>
      <td></td>
    </tr>
  </tbody>
</table>
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