# C1.LiveLinq.Indexing.ScannerCollection-1.Contains

## Content

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<h1 id="C1_LiveLinq_Indexing_ScannerCollection_1_Contains_" data-uid="C1.LiveLinq.Indexing.ScannerCollection`1.Contains*">Contains Method
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<div class="markdown level0 summary"></div>
<div class="markdown level0 conceptual"></div>



<a id="C1_LiveLinq_Indexing_ScannerCollection_1_Contains_" data-uid="C1.LiveLinq.Indexing.ScannerCollection`1.Contains*"></a>
<h4 id="C1_LiveLinq_Indexing_ScannerCollection_1_Contains_System_Linq_Expressions_LambdaExpression_" data-uid="C1.LiveLinq.Indexing.ScannerCollection`1.Contains(System.Linq.Expressions.LambdaExpression)">Contains(LambdaExpression)</h4>
<div class="markdown level1 summary"><p>Determines whether an index with the specified key selector exists in the collection.</p>
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<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
<div class="codewrapper">
  <pre><code class="lang-csharp hljs">public bool Contains(LambdaExpression keySelector)</code></pre>
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<div class="codewrapper">
  <pre><code class="lang-vbnet hljs">Public Function Contains(keySelector As LambdaExpression) As Boolean</code></pre>
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<h5 class="parameters">Parameters</h5>
<table class="table table-bordered table-condensed">
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      <th>Type</th>
      <th>Name</th>
      <th>Description</th>
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    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.linq.expressions.lambdaexpression">LambdaExpression</a></td>
      <td><span class="parametername">keySelector</span></td>
      <td><p>Key selector expression of an index, see <a class="xref" href="C1.LiveLinq.Indexing.IndexDefinition-1.KeySelector.html#C1_LiveLinq_Indexing_IndexDefinition_1_KeySelector">KeySelector</a>.</p>
</td>
    </tr>
  </tbody>
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<h5 class="returns">Returns</h5>
<table class="table table-bordered table-condensed">
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
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    <tr>
      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.boolean">bool</a></td>
      <td><p><b>true</b> if an index with the specified key selector is found in the collection; otherwise, <b>false</b>.</p>
</td>
    </tr>
  </tbody>
</table>


<a id="C1_LiveLinq_Indexing_ScannerCollection_1_Contains_" data-uid="C1.LiveLinq.Indexing.ScannerCollection`1.Contains*"></a>
<h4 id="C1_LiveLinq_Indexing_ScannerCollection_1_Contains__1_System_Linq_Expressions_Expression_System_Func__0___0___" data-uid="C1.LiveLinq.Indexing.ScannerCollection`1.Contains``1(System.Linq.Expressions.Expression{System.Func{`0,``0}})">Contains&lt;TKey&gt;(Expression&lt;Func&lt;T, TKey&gt;&gt;)</h4>
<div class="markdown level1 summary"><p>Determines whether an index with the specified key selector exists in the collection.</p>
</div>
<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
<div class="codewrapper">
  <pre><code class="lang-csharp hljs">public bool Contains&lt;TKey&gt;(Expression&lt;Func&lt;T, TKey&gt;&gt; keySelector)</code></pre>
</div>
<div class="codewrapper">
  <pre><code class="lang-vbnet hljs">Public Function Contains(Of TKey)(keySelector As Expression(Of Func(Of T, TKey))) As Boolean</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.linq.expressions.expression-1">Expression</a>&lt;<a class="xref" href="https://learn.microsoft.com/dotnet/api/system.func-2">Func</a>&lt;T, TKey&gt;&gt;</td>
      <td><span class="parametername">keySelector</span></td>
      <td><p>Key selector expression of an index, see <a class="xref" href="C1.LiveLinq.Indexing.IndexDefinition-1.KeySelector.html#C1_LiveLinq_Indexing_IndexDefinition_1_KeySelector">KeySelector</a>.</p>
</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.boolean">bool</a></td>
      <td><p><b>true</b> if an index with the specified key selector is found in the collection; otherwise, <b>false</b>.</p>
</td>
    </tr>
  </tbody>
</table>
<h5 class="typeParameters">Type Parameters</h5>
<table class="table table-bordered table-condensed">
  <thead>
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      <th>Name</th>
      <th>Description</th>
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    <tr>
      <td><span class="parametername">TKey</span></td>
      <td><p>The type of the index key.</p>
</td>
    </tr>
  </tbody>
</table>
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