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   <h1 id="Lucene_Net_Index_IndexReader" data-uid="Lucene.Net.Index.IndexReader" class="text-break">Class IndexReader
   </h1>
   <div class="markdown level0 summary"><p><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> is an abstract class, providing an interface for accessing an
 index.  Search of an index is done entirely through this abstract interface,
 so that any subclass which implements it is searchable.</p>
 <p><p>There are two different types of <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>s:
 <ul><li><a class="xref" href="Lucene.Net.Index.AtomicReader.html">AtomicReader</a>: These indexes do not consist of several sub-readers,
         they are atomic. They support retrieval of stored fields, doc values, terms,
         and postings.</li><li><a class="xref" href="Lucene.Net.Index.CompositeReader.html">CompositeReader</a>: Instances (like <a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a>)
         of this reader can only
         be used to get stored fields from the underlying <a class="xref" href="Lucene.Net.Index.AtomicReader.html">AtomicReader</a>s,
         but it is not possible to directly retrieve postings. To do that, get
         the sub-readers via <a class="xref" href="Lucene.Net.Index.CompositeReader.html#Lucene_Net_Index_CompositeReader_GetSequentialSubReaders">GetSequentialSubReaders()</a>.
         Alternatively, you can mimic an <a class="xref" href="Lucene.Net.Index.AtomicReader.html">AtomicReader</a> (with a serious slowdown),
         by wrapping composite readers with <a class="xref" href="Lucene.Net.Index.SlowCompositeReaderWrapper.html">SlowCompositeReaderWrapper</a>.</li></ul></p>
 <p><p><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> instances for indexes on disk are usually constructed
 with a call to one of the static <code>DirectoryReader.Open()</code> methods,
 e.g. <a class="xref" href="Lucene.Net.Index.DirectoryReader.html#Lucene_Net_Index_DirectoryReader_Open_Lucene_Net_Store_Directory_">Open(Directory)</a>. <a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a> inherits
 the <a class="xref" href="Lucene.Net.Index.CompositeReader.html">CompositeReader</a> abstract class, it is not possible to directly get postings.</p>
 <p><p> For efficiency, in this API documents are often referred to via
 <em>document numbers</em>, non-negative integers which each name a unique
 document in the index.  These document numbers are ephemeral -- they may change
 as documents are added to and deleted from an index.  Clients should thus not
 rely on a given document having the same number between sessions.</p>
 <p><p>
 <strong>NOTE</strong>: <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> instances are completely thread
 safe, meaning multiple threads can call any of its methods,
 concurrently.  If your application requires external
 synchronization, you should <strong>not</strong> synchronize on the
 <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> instance; use your own
 (non-Lucene) objects instead.</p>
 </div>
   <div class="markdown level0 conceptual"></div>
   <div class="inheritance">
     <h5>Inheritance</h5>
     <div class="level0"><span class="xref">System.Object</span></div>
     <div class="level1"><span class="xref">IndexReader</span></div>
       <div class="level2"><a class="xref" href="Lucene.Net.Index.AtomicReader.html">AtomicReader</a></div>
       <div class="level2"><a class="xref" href="Lucene.Net.Index.CompositeReader.html">CompositeReader</a></div>
   </div>
   <div classs="implements">
     <h5>Implements</h5>
     <div><span class="xref">System.IDisposable</span></div>
   </div>
   <div class="inheritedMembers">
     <h5>Inherited Members</h5>
     <div>
       <span class="xref">System.Object.Equals(System.Object, System.Object)</span>
     </div>
     <div>
       <span class="xref">System.Object.GetType()</span>
     </div>
     <div>
       <span class="xref">System.Object.MemberwiseClone()</span>
     </div>
     <div>
       <span class="xref">System.Object.ReferenceEquals(System.Object, System.Object)</span>
     </div>
     <div>
       <span class="xref">System.Object.ToString()</span>
     </div>
   </div>
   <h6><strong>Namespace</strong>: <a class="xref" href="Lucene.Net.Index.html">Lucene.Net.Index</a></h6>
   <h6><strong>Assembly</strong>: Lucene.Net.dll</h6>
   <h5 id="Lucene_Net_Index_IndexReader_syntax">Syntax</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract class IndexReader : IDisposable</code></pre>
   </div>
   <h3 id="properties">Properties
   </h3>
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   <a id="Lucene_Net_Index_IndexReader_CombinedCoreAndDeletesKey_" data-uid="Lucene.Net.Index.IndexReader.CombinedCoreAndDeletesKey*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_CombinedCoreAndDeletesKey" data-uid="Lucene.Net.Index.IndexReader.CombinedCoreAndDeletesKey">CombinedCoreAndDeletesKey</h4>
   <div class="markdown level1 summary"><p>Expert: Returns a key for this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> that also includes deletions,
 so <a class="xref" href="Lucene.Net.Search.IFieldCache.html">IFieldCache</a>/<a class="xref" href="Lucene.Net.Search.CachingWrapperFilter.html">CachingWrapperFilter</a> can find it again.
 This key must not have Equals()/GetHashCode() methods,
 so &quot;equals&quot; means &quot;identical&quot;.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual object CombinedCoreAndDeletesKey { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Object</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Context_" data-uid="Lucene.Net.Index.IndexReader.Context*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Context" data-uid="Lucene.Net.Index.IndexReader.Context">Context</h4>
   <div class="markdown level1 summary"><p>Expert: Returns the root <a class="xref" href="Lucene.Net.Index.IndexReaderContext.html">IndexReaderContext</a> for this
 <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>&apos;s sub-reader tree.
 <p>
 Iff this reader is composed of sub
 readers, i.e. this reader being a composite reader, this method returns a
 <a class="xref" href="Lucene.Net.Index.CompositeReaderContext.html">CompositeReaderContext</a> holding the reader&apos;s direct children as well as a
 view of the reader tree&apos;s atomic leaf contexts. All sub-
 <a class="xref" href="Lucene.Net.Index.IndexReaderContext.html">IndexReaderContext</a> instances referenced from this readers top-level
 context are private to this reader and are not shared with another context
 tree. For example, <a class="xref" href="Lucene.Net.Search.IndexSearcher.html">IndexSearcher</a> uses this API to drive searching by one
 atomic leaf reader at a time. If this reader is not composed of child
 readers, this method returns an <a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html">AtomicReaderContext</a>.
 <p>
 Note: Any of the sub-<a class="xref" href="Lucene.Net.Index.CompositeReaderContext.html">CompositeReaderContext</a> instances referenced
 from this top-level context do not support <a class="xref" href="Lucene.Net.Index.CompositeReaderContext.html#Lucene_Net_Index_CompositeReaderContext_Leaves">Leaves</a>.
 Only the top-level context maintains the convenience leaf-view
 for performance reasons.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract IndexReaderContext Context { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReaderContext.html">IndexReaderContext</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <a id="Lucene_Net_Index_IndexReader_CoreCacheKey_" data-uid="Lucene.Net.Index.IndexReader.CoreCacheKey*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_CoreCacheKey" data-uid="Lucene.Net.Index.IndexReader.CoreCacheKey">CoreCacheKey</h4>
   <div class="markdown level1 summary"><p>Expert: Returns a key for this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>, so
 <a class="xref" href="Lucene.Net.Search.IFieldCache.html">IFieldCache</a>/<a class="xref" href="Lucene.Net.Search.CachingWrapperFilter.html">CachingWrapperFilter</a> can find
 it again.
 This key must not have Equals()/GetHashCode() methods,
 so &quot;equals&quot; means &quot;identical&quot;.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual object CoreCacheKey { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Object</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <a id="Lucene_Net_Index_IndexReader_HasDeletions_" data-uid="Lucene.Net.Index.IndexReader.HasDeletions*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_HasDeletions" data-uid="Lucene.Net.Index.IndexReader.HasDeletions">HasDeletions</h4>
   <div class="markdown level1 summary"><p>Returns <code>true</code> if any documents have been deleted. Implementers should
 consider overriding this property if <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_MaxDoc">MaxDoc</a> or <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_NumDocs">NumDocs</a>
 are not constant-time operations.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public virtual bool HasDeletions { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <a id="Lucene_Net_Index_IndexReader_Leaves_" data-uid="Lucene.Net.Index.IndexReader.Leaves*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Leaves" data-uid="Lucene.Net.Index.IndexReader.Leaves">Leaves</h4>
   <div class="markdown level1 summary"><p>Returns the reader&apos;s leaves, or itself if this reader is atomic.
 This is a convenience method calling <code>this.Context.Leaves</code>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public IList&lt;AtomicReaderContext&gt; Leaves { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Collections.Generic.IList</span>&lt;<a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html">AtomicReaderContext</a>&gt;</td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_Leaves_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexReaderContext.html#Lucene_Net_Index_IndexReaderContext_Leaves">Leaves</a></div>
   </div>
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   <a id="Lucene_Net_Index_IndexReader_MaxDoc_" data-uid="Lucene.Net.Index.IndexReader.MaxDoc*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_MaxDoc" data-uid="Lucene.Net.Index.IndexReader.MaxDoc">MaxDoc</h4>
   <div class="markdown level1 summary"><p>Returns one greater than the largest possible document number.
 this may be used to, e.g., determine how big to allocate an array which
 will have an element for every document number in an index.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract int MaxDoc { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <h4 id="Lucene_Net_Index_IndexReader_NumDeletedDocs" data-uid="Lucene.Net.Index.IndexReader.NumDeletedDocs">NumDeletedDocs</h4>
   <div class="markdown level1 summary"><p>Returns the number of deleted documents. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public int NumDeletedDocs { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_NumDocs_" data-uid="Lucene.Net.Index.IndexReader.NumDocs*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_NumDocs" data-uid="Lucene.Net.Index.IndexReader.NumDocs">NumDocs</h4>
   <div class="markdown level1 summary"><p>Returns the number of documents in this index. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract int NumDocs { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexReader_RefCount_" data-uid="Lucene.Net.Index.IndexReader.RefCount*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_RefCount" data-uid="Lucene.Net.Index.IndexReader.RefCount">RefCount</h4>
   <div class="markdown level1 summary"><p>Expert: returns the current refCount for this reader </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public int RefCount { get; }</code></pre>
   </div>
   <h5 class="propertyValue">Property Value</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h3 id="methods">Methods
   </h3>
   <span class="small pull-right mobile-hide">
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_AddReaderClosedListener_Lucene_Net_Index_IndexReader_IReaderClosedListener_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.AddReaderClosedListener(Lucene.Net.Index.IndexReader.IReaderClosedListener)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_AddReaderClosedListener_" data-uid="Lucene.Net.Index.IndexReader.AddReaderClosedListener*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_AddReaderClosedListener_Lucene_Net_Index_IndexReader_IReaderClosedListener_" data-uid="Lucene.Net.Index.IndexReader.AddReaderClosedListener(Lucene.Net.Index.IndexReader.IReaderClosedListener)">AddReaderClosedListener(IndexReader.IReaderClosedListener)</h4>
   <div class="markdown level1 summary"><p>Expert: adds a <a class="xref" href="Lucene.Net.Index.IndexReader.IReaderClosedListener.html">IndexReader.IReaderClosedListener</a>.  The
 provided listener will be invoked when this reader is closed.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void AddReaderClosedListener(IndexReader.IReaderClosedListener listener)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReader.IReaderClosedListener.html">IndexReader.IReaderClosedListener</a></td>
         <td><span class="parametername">listener</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L262">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_DecRef_" data-uid="Lucene.Net.Index.IndexReader.DecRef*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_DecRef" data-uid="Lucene.Net.Index.IndexReader.DecRef">DecRef()</h4>
   <div class="markdown level1 summary"><p>Expert: decreases the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a> of this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>
 instance.  If the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a> drops to 0, then this
 reader is disposed.  If an exception is hit, the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a>
 is unchanged.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void DecRef()</code></pre>
   </div>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>in case an <span class="xref">System.IO.IOException</span> occurs in <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DoClose">DoClose()</a></p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_DecRef_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_IncRef">IncRef()</a></div>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Dispose_" data-uid="Lucene.Net.Index.IndexReader.Dispose*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Dispose" data-uid="Lucene.Net.Index.IndexReader.Dispose">Dispose()</h4>
   <div class="markdown level1 summary"><p>Closes files associated with this index.
 Also saves any new deletions to disk.
 No other methods should be called after this has been called.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void Dispose()</code></pre>
   </div>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>If there is a low-level IO error</p>
 </td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Dispose_" data-uid="Lucene.Net.Index.IndexReader.Dispose*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Dispose_System_Boolean_" data-uid="Lucene.Net.Index.IndexReader.Dispose(System.Boolean)">Dispose(Boolean)</h4>
   <div class="markdown level1 summary"><p>Closes files associated with this index.
 This method implements the disposable pattern.
 It may be overridden to dispose any managed or unmanaged resources,
 but be sure to call <code>base.Dispose(disposing)</code> to close files associated with the
 underlying <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected virtual void Dispose(bool disposing)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">disposing</span></td>
         <td><p><code>true</code> indicates to dispose all managed
     and unmanaged resources, <code>false</code> indicates dispose unmanaged
     resources only</p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_DocFreq_" data-uid="Lucene.Net.Index.IndexReader.DocFreq*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_DocFreq_Lucene_Net_Index_Term_" data-uid="Lucene.Net.Index.IndexReader.DocFreq(Lucene.Net.Index.Term)">DocFreq(Term)</h4>
   <div class="markdown level1 summary"><p>Returns the number of documents containing the
 <code data-dev-comment-type="paramref" class="paramref">term</code>.  This method returns 0 if the term or
 field does not exist.  This method does not take into
 account deleted documents that have not yet been merged
 away. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract int DocFreq(Term term)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_DocFreq_Lucene_Net_Index_Term__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.TermsEnum.html#Lucene_Net_Index_TermsEnum_DocFreq">DocFreq</a></div>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_DoClose_" data-uid="Lucene.Net.Index.IndexReader.DoClose*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_DoClose" data-uid="Lucene.Net.Index.IndexReader.DoClose">DoClose()</h4>
   <div class="markdown level1 summary"><p>Implements close. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected abstract void DoClose()</code></pre>
   </div>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Document_" data-uid="Lucene.Net.Index.IndexReader.Document*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Document_System_Int32_" data-uid="Lucene.Net.Index.IndexReader.Document(System.Int32)">Document(Int32)</h4>
   <div class="markdown level1 summary"><p>Returns the stored fields of the <code>n</code><sup>th</sup>
 <a class="xref" href="Lucene.Net.Documents.Document.html">Document</a> in this index.  This is just
 sugar for using <a class="xref" href="Lucene.Net.Documents.DocumentStoredFieldVisitor.html">DocumentStoredFieldVisitor</a>.
 <p>
 <strong>NOTE:</strong> for performance reasons, this method does not check if the
 requested document is deleted, and therefore asking for a deleted document
 may yield unspecified results. Usually this is not required, however you
 can test if the doc is deleted by checking the
 <a class="xref" href="Lucene.Net.Util.IBits.html">IBits</a> returned from <a class="xref" href="Lucene.Net.Index.MultiFields.html#Lucene_Net_Index_MultiFields_GetLiveDocs_Lucene_Net_Index_IndexReader_">GetLiveDocs(IndexReader)</a>.
 <p>
 <strong>NOTE:</strong> only the content of a field is returned,
 if that field was stored during indexing.  Metadata
 like boost, omitNorm, IndexOptions, tokenized, etc.,
 are not preserved.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public Document Document(int docID)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Documents.Document.html">Document</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Document_" data-uid="Lucene.Net.Index.IndexReader.Document*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Document_System_Int32_Lucene_Net_Index_StoredFieldVisitor_" data-uid="Lucene.Net.Index.IndexReader.Document(System.Int32,Lucene.Net.Index.StoredFieldVisitor)">Document(Int32, StoredFieldVisitor)</h4>
   <div class="markdown level1 summary"><p>Expert: visits the fields of a stored document, for
 custom processing/loading of each field. If you
 simply want to load all fields, use
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_Document_System_Int32_">Document(Int32)</a>. If you want to load a subset, use
 <a class="xref" href="Lucene.Net.Documents.DocumentStoredFieldVisitor.html">DocumentStoredFieldVisitor</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract void Document(int docID, StoredFieldVisitor visitor)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.StoredFieldVisitor.html">StoredFieldVisitor</a></td>
         <td><span class="parametername">visitor</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_Document_System_Int32_System_Collections_Generic_ISet_System_String__.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.Document(System.Int32%2CSystem.Collections.Generic.ISet%7BSystem.String%7D)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L514">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Document_" data-uid="Lucene.Net.Index.IndexReader.Document*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Document_System_Int32_System_Collections_Generic_ISet_System_String__" data-uid="Lucene.Net.Index.IndexReader.Document(System.Int32,System.Collections.Generic.ISet{System.String})">Document(Int32, ISet&lt;String&gt;)</h4>
   <div class="markdown level1 summary"><p>Like <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_Document_System_Int32_">Document(Int32)</a> but only loads the specified
 fields.  Note that this is simply sugar for
 <a class="xref" href="Lucene.Net.Documents.DocumentStoredFieldVisitor.html#Lucene_Net_Documents_DocumentStoredFieldVisitor__ctor_System_Collections_Generic_ISet_System_String__">DocumentStoredFieldVisitor(ISet&lt;String&gt;)</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public Document Document(int docID, ISet&lt;string&gt; fieldsToLoad)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.Collections.Generic.ISet</span>&lt;<span class="xref">System.String</span>&gt;</td>
         <td><span class="parametername">fieldsToLoad</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Documents.Document.html">Document</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_EnsureOpen.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.EnsureOpen%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L306">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_EnsureOpen_" data-uid="Lucene.Net.Index.IndexReader.EnsureOpen*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_EnsureOpen" data-uid="Lucene.Net.Index.IndexReader.EnsureOpen">EnsureOpen()</h4>
   <div class="markdown level1 summary"><p>Throws <span class="xref">System.ObjectDisposedException</span> if this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> or any
 of its child readers is disposed, otherwise returns.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">protected void EnsureOpen()</code></pre>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_Equals_System_Object_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.Equals(System.Object)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L327">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Equals_" data-uid="Lucene.Net.Index.IndexReader.Equals*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Equals_System_Object_" data-uid="Lucene.Net.Index.IndexReader.Equals(System.Object)">Equals(Object)</h4>
   <div class="markdown level1 summary"><p>Determines whether two object instances are equal.
 <p>For caching purposes, <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> subclasses are not allowed
 to implement Equals/GetHashCode, so methods are declared sealed.
 To lookup instances from caches use <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_CoreCacheKey">CoreCacheKey</a> and
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_CombinedCoreAndDeletesKey">CombinedCoreAndDeletesKey</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public override sealed bool Equals(object obj)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Object</span></td>
         <td><span class="parametername">obj</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="overrides">Overrides</h5>
   <div><span class="xref">System.Object.Equals(System.Object)</span></div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetDocCount_System_String_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetDocCount(System.String)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L649">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_GetDocCount_" data-uid="Lucene.Net.Index.IndexReader.GetDocCount*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetDocCount_System_String_" data-uid="Lucene.Net.Index.IndexReader.GetDocCount(System.String)">GetDocCount(String)</h4>
   <div class="markdown level1 summary"><p>Returns the number of documents that have at least one term for this field,
 or -1 if this measure isn&apos;t stored by the codec. Note that, just like other
 term measures, this measure does not take deleted documents into account.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract int GetDocCount(string field)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_GetDocCount_System_String__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.Terms.html#Lucene_Net_Index_Terms_DocCount">DocCount</a></div>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetHashCode.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetHashCode%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L339">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_GetHashCode_" data-uid="Lucene.Net.Index.IndexReader.GetHashCode*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetHashCode" data-uid="Lucene.Net.Index.IndexReader.GetHashCode">GetHashCode()</h4>
   <div class="markdown level1 summary"><p>Serves as the default hash function.
 <p>For caching purposes, <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> subclasses are not allowed
 to implement Equals/GetHashCode, so methods are declared sealed.
 To lookup instances from caches use <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_CoreCacheKey">CoreCacheKey</a> and
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_CombinedCoreAndDeletesKey">CombinedCoreAndDeletesKey</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public override sealed int GetHashCode()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="overrides">Overrides</h5>
   <div><span class="xref">System.Object.GetHashCode()</span></div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetSumDocFreq_System_String_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetSumDocFreq(System.String)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_GetSumDocFreq_" data-uid="Lucene.Net.Index.IndexReader.GetSumDocFreq*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetSumDocFreq_System_String_" data-uid="Lucene.Net.Index.IndexReader.GetSumDocFreq(System.String)">GetSumDocFreq(String)</h4>
   <div class="markdown level1 summary"><p>Returns the sum of <a class="xref" href="Lucene.Net.Index.TermsEnum.html#Lucene_Net_Index_TermsEnum_DocFreq">DocFreq</a> for all terms in this field,
 or -1 if this measure isn&apos;t stored by the codec. Note that, just like other
 term measures, this measure does not take deleted documents into account.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract long GetSumDocFreq(string field)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int64</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_GetSumDocFreq_System_String__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.Terms.html#Lucene_Net_Index_Terms_SumDocFreq">SumDocFreq</a></div>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetSumTotalTermFreq_System_String_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetSumTotalTermFreq(System.String)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_GetSumTotalTermFreq_" data-uid="Lucene.Net.Index.IndexReader.GetSumTotalTermFreq*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetSumTotalTermFreq_System_String_" data-uid="Lucene.Net.Index.IndexReader.GetSumTotalTermFreq(System.String)">GetSumTotalTermFreq(String)</h4>
   <div class="markdown level1 summary"><p>Returns the sum of <a class="xref" href="Lucene.Net.Index.TermsEnum.html#Lucene_Net_Index_TermsEnum_TotalTermFreq">TotalTermFreq</a> for all terms in this
 field, or -1 if this measure isn&apos;t stored by the codec (or if this fields
 omits term freq and positions). Note that, just like other term measures,
 this measure does not take deleted documents into account.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract long GetSumTotalTermFreq(string field)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int64</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_GetSumTotalTermFreq_System_String__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.Terms.html#Lucene_Net_Index_Terms_SumTotalTermFreq">SumTotalTermFreq</a></div>
   </div>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetTermVector_System_Int32_System_String_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetTermVector(System.Int32%2CSystem.String)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L448">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_GetTermVector_" data-uid="Lucene.Net.Index.IndexReader.GetTermVector*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetTermVector_System_Int32_System_String_" data-uid="Lucene.Net.Index.IndexReader.GetTermVector(System.Int32,System.String)">GetTermVector(Int32, String)</h4>
   <div class="markdown level1 summary"><p>Retrieve term vector for this document and field, or
 <code>null</code> if term vectors were not indexed. The returned
 <a class="xref" href="Lucene.Net.Index.Fields.html">Fields</a> instance acts like a single-document inverted
 index (the docID will be 0).</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public Terms GetTermVector(int docID, string field)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
       <tr>
         <td><span class="xref">System.String</span></td>
         <td><span class="parametername">field</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Terms.html">Terms</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
     <span class="divider">|</span>
     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_GetTermVectors_System_Int32_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.GetTermVectors(System.Int32)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L440">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_GetTermVectors_" data-uid="Lucene.Net.Index.IndexReader.GetTermVectors*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_GetTermVectors_System_Int32_" data-uid="Lucene.Net.Index.IndexReader.GetTermVectors(System.Int32)">GetTermVectors(Int32)</h4>
   <div class="markdown level1 summary"><p>Retrieve term vectors for this document, or <code>null</code> if
 term vectors were not indexed. The returned <a class="xref" href="Lucene.Net.Index.Fields.html">Fields</a>
 instance acts like a single-document inverted index
 (the docID will be 0).</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract Fields GetTermVectors(int docID)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">docID</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Fields.html">Fields</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <span class="small pull-right mobile-hide">
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_IncRef.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.IncRef%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
   </span>
   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L210">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_IncRef_" data-uid="Lucene.Net.Index.IndexReader.IncRef*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_IncRef" data-uid="Lucene.Net.Index.IndexReader.IncRef">IncRef()</h4>
   <div class="markdown level1 summary"><p>Expert: increments the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a> of this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>
 instance.  <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a>s are used to determine when a
 reader can be disposed safely, i.e. as soon as there are
 no more references.  Be sure to always call a
 corresponding <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a>, in a finally clause;
 otherwise the reader may never be disposed.  Note that
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_Dispose_System_Boolean_">Dispose(Boolean)</a> simply calls <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a>, which means that
 the <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> will not really be disposed until
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a> has been called for all outstanding
 references.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void IncRef()</code></pre>
   </div>
   <h5 id="Lucene_Net_Index_IndexReader_IncRef_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a></div>
       <div><a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_TryIncRef">TryIncRef()</a></div>
   </div>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_Open_Lucene_Net_Index_IndexCommit_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.Open(Lucene.Net.Index.IndexCommit)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L406">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Open_" data-uid="Lucene.Net.Index.IndexReader.Open*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Index_IndexCommit_" data-uid="Lucene.Net.Index.IndexReader.Open(Lucene.Net.Index.IndexCommit)">Open(IndexCommit)</h4>
   <div class="markdown level1 summary"><p>Expert: returns an <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> reading the index in the given
 <a class="xref" href="Lucene.Net.Index.IndexCommit.html">IndexCommit</a>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">[Obsolete(&quot;Use DirectoryReader.Open(IndexCommit)&quot;)]
 public static DirectoryReader Open(IndexCommit commit)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexCommit.html">IndexCommit</a></td>
         <td><span class="parametername">commit</span></td>
         <td><p>the commit point to open </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L428">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Open_" data-uid="Lucene.Net.Index.IndexReader.Open*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Index_IndexCommit_System_Int32_" data-uid="Lucene.Net.Index.IndexReader.Open(Lucene.Net.Index.IndexCommit,System.Int32)">Open(IndexCommit, Int32)</h4>
   <div class="markdown level1 summary"><p>Expert: returns an <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> reading the index in the given
 <a class="xref" href="Lucene.Net.Index.IndexCommit.html">IndexCommit</a> and <code data-dev-comment-type="paramref" class="paramref">termInfosIndexDivisor</code>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">[Obsolete(&quot;Use DirectoryReader.Open(IndexCommit, int)/&gt;&quot;)]
 public static DirectoryReader Open(IndexCommit commit, int termInfosIndexDivisor)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexCommit.html">IndexCommit</a></td>
         <td><span class="parametername">commit</span></td>
         <td><p>the commit point to open </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">termInfosIndexDivisor</span></td>
         <td><p>Subsamples which indexed
 terms are loaded into RAM. this has the same effect as
 <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_TermIndexInterval">TermIndexInterval</a>
 (which can be set in <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html">IndexWriterConfig</a>) except that setting
 must be done at indexing time while this setting can be
 set per reader.  When set to <code>N</code>, then one in every
 <code>N*termIndexInterval</code> terms in the index is loaded into
 memory.  By setting this to a value <code>&gt; 1</code> you can reduce
 memory usage, at the expense of higher latency when
 loading a TermInfo.  The default value is 1.  Set this
 to -1 to skip loading the terms index entirely. </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L394">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Open_" data-uid="Lucene.Net.Index.IndexReader.Open*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Index_IndexWriter_System_Boolean_" data-uid="Lucene.Net.Index.IndexReader.Open(Lucene.Net.Index.IndexWriter,System.Boolean)">Open(IndexWriter, Boolean)</h4>
   <div class="markdown level1 summary"><p>Open a near real time <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> from the <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">[Obsolete(&quot;Use DirectoryReader.Open(IndexWriter, bool)&quot;)]
 public static DirectoryReader Open(IndexWriter writer, bool applyAllDeletes)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a></td>
         <td><span class="parametername">writer</span></td>
         <td><p>The <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a> to open from </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td><span class="parametername">applyAllDeletes</span></td>
         <td><p>If true, all buffered deletes will
 be applied (made visible) in the returned reader.  If
 false, the deletes are not applied but remain buffered
 (in <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>) so that they will be applied in the
 future.  Applying deletes can be costly, so if your app
 can tolerate deleted documents being returned you might
 gain some performance by passing false. </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td><p>The new <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error</p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Index_IndexWriter_System_Boolean__seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.DirectoryReader.html#Lucene_Net_Index_DirectoryReader_OpenIfChanged_Lucene_Net_Index_DirectoryReader_Lucene_Net_Index_IndexWriter_System_Boolean_">OpenIfChanged</a>(<a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a>, <a class="xref" href="Lucene.Net.Index.IndexWriter.html">IndexWriter</a>, <span class="xref">System.Boolean</span>)</div>
   </div>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_Open_Lucene_Net_Store_Directory_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.Open(Lucene.Net.Store.Directory)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L349">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_Open_" data-uid="Lucene.Net.Index.IndexReader.Open*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Store_Directory_" data-uid="Lucene.Net.Index.IndexReader.Open(Lucene.Net.Store.Directory)">Open(Directory)</h4>
   <div class="markdown level1 summary"><p>Returns a <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> reading the index in the given
 <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">[Obsolete(&quot;Use DirectoryReader.Open(Directory)&quot;)]
 public static DirectoryReader Open(Directory directory)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td><span class="parametername">directory</span></td>
         <td><p>the index directory </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_Open_" data-uid="Lucene.Net.Index.IndexReader.Open*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_Open_Lucene_Net_Store_Directory_System_Int32_" data-uid="Lucene.Net.Index.IndexReader.Open(Lucene.Net.Store.Directory,System.Int32)">Open(Directory, Int32)</h4>
   <div class="markdown level1 summary"><p>Expert: Returns a <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> reading the index in the given
 <a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a> with the given <code data-dev-comment-type="paramref" class="paramref">termInfosIndexDivisor</code>. </p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">[Obsolete(&quot;Use DirectoryReader.Open(Directory, int)&quot;)]
 public static DirectoryReader Open(Directory directory, int termInfosIndexDivisor)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Store.Directory.html">Directory</a></td>
         <td><span class="parametername">directory</span></td>
         <td><p>the index directory </p>
 </td>
       </tr>
       <tr>
         <td><span class="xref">System.Int32</span></td>
         <td><span class="parametername">termInfosIndexDivisor</span></td>
         <td><p>Subsamples which indexed
 terms are loaded into RAM. this has the same effect as
 <a class="xref" href="Lucene.Net.Index.LiveIndexWriterConfig.html#Lucene_Net_Index_LiveIndexWriterConfig_TermIndexInterval">TermIndexInterval</a>
 (which can be set on <a class="xref" href="Lucene.Net.Index.IndexWriterConfig.html">IndexWriterConfig</a>) except that setting
 must be done at indexing time while this setting can be
 set per reader.  When set to <code>N</code>, then one in every
 <code>N*termIndexInterval</code> terms in the index is loaded into
 memory.  By setting this to a value <code>&gt; 1</code> you can reduce
 memory usage, at the expense of higher latency when
 loading a TermInfo.  The default value is 1.  Set this
 to -1 to skip loading the terms index entirely. </p>
 </td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.DirectoryReader.html">DirectoryReader</a></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="exceptions">Exceptions</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Condition</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.IO.IOException</span></td>
         <td><p>if there is a low-level IO error </p>
 </td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
     <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00010/src/Lucene.Net/Index/IndexReader.cs/#L136">View Source</a>
   </span>
   <a id="Lucene_Net_Index_IndexReader_RegisterParentReader_" data-uid="Lucene.Net.Index.IndexReader.RegisterParentReader*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_RegisterParentReader_Lucene_Net_Index_IndexReader_" data-uid="Lucene.Net.Index.IndexReader.RegisterParentReader(Lucene.Net.Index.IndexReader)">RegisterParentReader(IndexReader)</h4>
   <div class="markdown level1 summary"><p>Expert: this method is called by <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>s which wrap other readers
 (e.g. <a class="xref" href="Lucene.Net.Index.CompositeReader.html">CompositeReader</a> or <a class="xref" href="Lucene.Net.Index.FilterAtomicReader.html">FilterAtomicReader</a>) to register the parent
 at the child (this reader) on construction of the parent. When this reader is disposed,
 it will mark all registered parents as disposed, too. The references to parent readers
 are weak only, so they can be GCed once they are no longer in use.</p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void RegisterParentReader(IndexReader reader)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a></td>
         <td><span class="parametername">reader</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexReader_RemoveReaderClosedListener_" data-uid="Lucene.Net.Index.IndexReader.RemoveReaderClosedListener*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_RemoveReaderClosedListener_Lucene_Net_Index_IndexReader_IReaderClosedListener_" data-uid="Lucene.Net.Index.IndexReader.RemoveReaderClosedListener(Lucene.Net.Index.IndexReader.IReaderClosedListener)">RemoveReaderClosedListener(IndexReader.IReaderClosedListener)</h4>
   <div class="markdown level1 summary"><p>Expert: remove a previously added <a class="xref" href="Lucene.Net.Index.IndexReader.IReaderClosedListener.html">IndexReader.IReaderClosedListener</a>.
 <p>
 <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div></div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public void RemoveReaderClosedListener(IndexReader.IReaderClosedListener listener)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.IndexReader.IReaderClosedListener.html">IndexReader.IReaderClosedListener</a></td>
         <td><span class="parametername">listener</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_TotalTermFreq_Lucene_Net_Index_Term_.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.TotalTermFreq(Lucene.Net.Index.Term)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   <span class="small pull-right mobile-hide">
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   </span>
   <a id="Lucene_Net_Index_IndexReader_TotalTermFreq_" data-uid="Lucene.Net.Index.IndexReader.TotalTermFreq*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_TotalTermFreq_Lucene_Net_Index_Term_" data-uid="Lucene.Net.Index.IndexReader.TotalTermFreq(Lucene.Net.Index.Term)">TotalTermFreq(Term)</h4>
   <div class="markdown level1 summary"><p>Returns the total number of occurrences of <code data-dev-comment-type="paramref" class="paramref">term</code> across all
 documents (the sum of the Freq for each doc that has this term). This
 will be -1 if the codec doesn&apos;t support this measure. Note that, like other
 term measures, this measure does not take deleted documents into account.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public abstract long TotalTermFreq(Term term)</code></pre>
   </div>
   <h5 class="parameters">Parameters</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Name</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><a class="xref" href="Lucene.Net.Index.Term.html">Term</a></td>
         <td><span class="parametername">term</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Int64</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
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     <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00010/websites/apidocs/apiSpec/new?filename=Lucene_Net_Index_IndexReader_TryIncRef.md&amp;value=---%0Auid%3A%20Lucene.Net.Index.IndexReader.TryIncRef%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a>
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   </span>
   <a id="Lucene_Net_Index_IndexReader_TryIncRef_" data-uid="Lucene.Net.Index.IndexReader.TryIncRef*"></a>
   <h4 id="Lucene_Net_Index_IndexReader_TryIncRef" data-uid="Lucene.Net.Index.IndexReader.TryIncRef">TryIncRef()</h4>
   <div class="markdown level1 summary"><p>Expert: increments the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a> of this <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a>
 instance only if the <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> has not been disposed yet
 and returns <code>true</code> iff the <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a> was
 successfully incremented, otherwise <code>false</code>.
 If this method returns <code>false</code> the reader is either
 already disposed or is currently being disposed. Either way this
 reader instance shouldn&apos;t be used by an application unless
 <code>true</code> is returned.
 <p>
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_RefCount">RefCount</a>s are used to determine when a
 reader can be disposed safely, i.e. as soon as there are
 no more references.  Be sure to always call a
 corresponding <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a>, in a finally clause;
 otherwise the reader may never be disposed.  Note that
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_Dispose_System_Boolean_">Dispose(Boolean)</a> simply calls <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a>, which means that
 the <a class="xref" href="Lucene.Net.Index.IndexReader.html">IndexReader</a> will not really be disposed until
 <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a> has been called for all outstanding
 references.</p>
 </div>
   <div class="markdown level1 conceptual"></div>
   <h5 class="decalaration">Declaration</h5>
   <div class="codewrapper">
     <pre><code class="lang-csharp hljs">public bool TryIncRef()</code></pre>
   </div>
   <h5 class="returns">Returns</h5>
   <table class="table table-bordered table-striped table-condensed">
     <thead>
       <tr>
         <th>Type</th>
         <th>Description</th>
       </tr>
     </thead>
     <tbody>
       <tr>
         <td><span class="xref">System.Boolean</span></td>
         <td></td>
       </tr>
     </tbody>
   </table>
   <h5 id="Lucene_Net_Index_IndexReader_TryIncRef_seealso">See Also</h5>
   <div class="seealso">
       <div><a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_DecRef">DecRef()</a></div>
       <div><a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_IncRef">IncRef()</a></div>
   </div>
   <h3 id="implements">Implements</h3>
   <div>
       <span class="xref">System.IDisposable</span>
   </div>
 </article>
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