# GrapeCity.Spreadsheet.ExternalVariable.OnDirtying

## Content

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<h1 id="GrapeCity_Spreadsheet_ExternalVariable_OnDirtying_" data-uid="GrapeCity.Spreadsheet.ExternalVariable.OnDirtying*">OnDirtying Method
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<a id="GrapeCity_Spreadsheet_ExternalVariable_OnDirtying_" data-uid="GrapeCity.Spreadsheet.ExternalVariable.OnDirtying*"></a>
<h4 id="GrapeCity_Spreadsheet_ExternalVariable_OnDirtying" data-uid="GrapeCity.Spreadsheet.ExternalVariable.OnDirtying">OnDirtying()</h4>
<div class="markdown level1 summary"><p>Designates this external variable to be recalculated when the next recalculation occurs.</p>
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<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">protected virtual bool OnDirtying()</code></pre>
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  <pre><code class="lang-vbnet hljs">Protected Overridable Function OnDirtying() As Boolean</code></pre>
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<h5 class="returns">Returns</h5>
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      <th>Description</th>
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      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.boolean">bool</a></td>
      <td><p><code>true</code> if the external variable require executing its own logic (invoke <a class="xref" href="GrapeCity.Spreadsheet.ExternalVariable.OnDirtied.html#GrapeCity_Spreadsheet_ExternalVariable_OnDirtied">OnDirtied()</a>) after the calculation engine is ready; otherwise, <code>false</code>.</p>
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<h5 id="GrapeCity_Spreadsheet_ExternalVariable_OnDirtying_remarks">Remarks</h5>
<div class="markdown level1 remarks"><p>Accessing calculation engine (like get value of external variable) isn't available inside this function.</p>
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