.NET API for Search & Index

This .NET API enhances your apps to perform robust search & index operations based on fuzzy as well as synonym algorithms. Supports several types of searches.

Document Search Processing Features

Create an index in memory or on the local disk.
Merge several indexes.
Improve search performance by optimizing the index.
Index password-protected files.
Index with stop words.
Support for indexing additional fields.
Supports blended characters.
Support for characters indexed as a whole word.
Support for character replacement during indexing.
Support for custom text extractors.
Option for compact and metadata index.
Save extracted text in index with different levels of compression.
Document filtering during indexing.
Delete indexed paths from the index.
Filter documents in search results.
Search for different object types, such as text, numbers, dates, filenames, etc.
Combining different types of search into one search query.
Alias substitution in search queries.
Perform spell check during the search.
Perform keyboard layout correction during the search.
Search queries in text or flexible object form.
Highlighting search results in the text of the entire document or in text segments.
Multiple simultaneous thread-safe searches.
Thread-safe search during indexing, updating, or merging operation.
Search over several indexes simultaneously.

Indexing Content Supported File Formats

Indexing Metadata Supported File Formats

Word Processing: DOC, DOT, DOCX, DOCM, DOTX, DOTM, TXT, ODT, OTT, RTF
Spreadsheets: XLS, XLT, XLSX, XLSM, XLSB, XLTX, XLTM, XLA, XLAM, ODS, OTS, CSV, TSV, XML
Presentations: PPT, PPS, POT, PPTX, PPTM, POTX, POTM, PPSX, PPSM, ODP
Emails: PST, OST, EML, EMLX, MSG
OneNote: ONE
Archives: ZIP
Audio: MP3, WAV
Portable: PDF
Markup: HTML, XHTML, MHTML, MD, XML
eBook: CHM, EPUB, FB2
Image: BMP, GIF, JP2, PNG, WEBP, TIFF, JPG, PSD, DJVU
Medical Imaging: DCM, DICOM
Metafiles: EMF, WMF
Microsoft Project: MPP
Torrent: TORRENT
Visio Diagram: VSD, VSS
Video: AVI, MOV, QT, FLV, ASF

Supported Search Types

Simple word
Boolean
Regular expression
Faceted
Case sensitive
Flexible fuzzy
Synonym
Homophone
Wildcard
Phrase
Data range
Numeric range
Search by chunks
Object type search

Platform Independence

GroupDocs.Search for .NET does not require any external software or third-party tool to be installed. GroupDocs.Search for .NET supports any 32-bit or 64-bit operating system where the .NET or Mono framework is installed. The other details are as follows:

Microsoft Windows: Microsoft Windows Desktop (x86, x64) (XP & up), Microsoft Windows Server (x86, x64) (2000 & up), Windows Azure
Mac OS: Mac OS X
Linux: Linux (Ubuntu, OpenSUSE, CentOS and others)
Development Environments: Microsoft Visual Studio (2010 & up), Xamarin.Android, Xamarin.IOS, Xamarin.Mac, MonoDevelop 2.4 and later.
Supported Frameworks: GroupDocs.Conversion for .NET supports .NET and Mono frameworks.

Get Started

Are you ready to give GroupDocs.Search for .NET a try? Simply execute Install-Package GroupDocs.Search from Package Manager Console in Visual Studio to fetch & reference GroupDocs.Search assembly in your project. If you already have GroupDocs.Search for .Net and want to upgrade it, please execute Update-Package GroupDocs.Search to get the latest version.

Please check the GitHub Repository for other common usage scenarios.

Use C# to Perform Regular Expression Search

string indexFolder = @"c:\MyIndex\";
string documentsFolder = @"c:\MyDocuments\";

// creating an index in the specified folder
Index index = new Index(indexFolder);

// indexing documents from the specified folder
index.Add(documentsFolder);

// search for the phrase in text form
// the first caret character at the beginning indicates that this is a regular expression search query
string query1 = "^^(.)\\1{1,}";
// search for two or more identical characters at the beginning of a word
SearchResult result1 = index.Search(query1); 

// search for the phrase in object form
// search for two or more identical characters at the beginning of a word
SearchQuery query2 = SearchQuery.CreateRegexQuery("^(.)\\1{1,}");
SearchResult result2 = index.Search(query2);

Spell Check with Smart Search via C# Code

string indexFolder = @"c:\MyIndex\";
string documentsFolder = @"c:\MyDocuments\";

// creating an index in the specified folder
Index index = new Index(indexFolder);

// indexing documents from the specified folder
index.Add(documentsFolder);

// creating search options instance
SearchOptions options = new SearchOptions();
// enabling the spelling correction
options.SpellingCorrector.Enabled = true;
// setting the maximum number of mistakes
options.SpellingCorrector.MaxMistakeCount = 1;
// enabling the option for only the best results of the spelling correction
options.SpellingCorrector.OnlyBestResults = true;

// search for the word "Rleativity" containing a spelling error
// the word "Relativity" will be found that differs from the search query in two transposed letters
SearchResult result = index.Search("Rleativity", options);