# C1.Win.Command.C1TopicPage.OnCollapse

## Content

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<h1 id="C1_Win_Command_C1TopicPage_OnCollapse_" data-uid="C1.Win.Command.C1TopicPage.OnCollapse*">OnCollapse Method
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<a id="C1_Win_Command_C1TopicPage_OnCollapse_" data-uid="C1.Win.Command.C1TopicPage.OnCollapse*"></a>
<h4 id="C1_Win_Command_C1TopicPage_OnCollapse" data-uid="C1.Win.Command.C1TopicPage.OnCollapse">OnCollapse()</h4>
<div class="markdown level1 summary"><p>Calls when <a class="xref" href="C1.Win.Command.C1TopicBar.html">C1TopicBar</a> page collapsed.</p>
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<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">protected virtual void OnCollapse()</code></pre>
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  <pre><code class="lang-vbnet hljs">Protected Overridable Sub OnCollapse()</code></pre>
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