ProvideLanguageCodeExpansionAttribute Class


Registers language service support for code snippets.

public ref class ProvideLanguageCodeExpansionAttribute sealed : Microsoft::VisualStudio::Shell::RegistrationAttribute
public ref class ProvideLanguageCodeExpansionAttribute sealed : Microsoft::VisualStudio::Shell::RegistrationAttribute
[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)]
public sealed class ProvideLanguageCodeExpansionAttribute : Microsoft.VisualStudio.Shell.RegistrationAttribute
type ProvideLanguageCodeExpansionAttribute = class
    inherit RegistrationAttribute
Public NotInheritable Class ProvideLanguageCodeExpansionAttribute
Inherits RegistrationAttribute


This example shows how this user-defined attribute is used to register support for code snippets for a language service.


Visual C# allows for a shorthand form of a user-defined attribute by dropping the "Attribute" part of the name. This shorthand form is used in this and all other examples throughout this class.

using Microsoft.VisualStudio.Shell;  
namespace MyLanguagePackage  
    internal class MyConstants  
        public const string languageName           = "MyLanguage";  
        public const int    languageNameResourceID = 106;  
        public const string languageIdentifier     = "mylanguage";  
        public const string snippetsIndexFilePath   = @"%InstallRoot%\MyLanguage\SnippetsIndex.xml";  
        // Optional code expansion properties  
        SearchPaths = @"%InstallRoot%\MyLanguage\Snippets\%LCID%\Snippets;" +  
                      @"\%MyDocs%\Code Snippets\MyLanguage\My Code Snippets";  
    class MyLanguagePackage  


This user-defined attribute (which is specific to C#) is used to provide information necessary to register a language service's support for code snippets with Visual Studio. The values specified by this attribute are stored as metadata in the assembly. This metadata is later used by a program such as regpkg.exe program (part of the VSIP SDK) to create the corresponding registry keys and entries that tell Visual Studio about the language service.

The registry entries affected by the ProvideLanguageCodeExpansionAttribute are found under the following registry key:

              [language name]\  
                (Default)    = reg_sz: [Language Service GUID]  
                DisplayName  = reg_sz: [language name resource ID]  
                IndexPath    = reg_sz: [path to snippet index file]  
                Package      = reg_sz: [Package GUID]  
                LangStringID = reg_sz: [language identifier]  
                  (Default)       = reg_sz:  
                  [language name] = reg_sz: [paths to snippets]  


  • [X.Y] is the version of Visual Studio, for example, 8.0Exp.

  • [language name] is the name of the language (as specified in the second parameter to the ProvideLanguageCodeExpansionAttribute class constructor).

  • [language name resource ID] is the resource ID of the language name that is used for display purposes and can therefore be localized.

  • [path to snippet index file] is the full path to the index file that describes the location of the snippets.

  • [language identifier] is a string used to mark all snippets and the snippets index file. This string is used to associate a set of snippets with a particular language service.

  • [paths to snippets] a semi-colon-delimited list of paths to search for snippets if the index file is not available.

The paths can contain substitution variables that point to locations such as the installed root for Visual Studio and the user's My Documents location. See Support for Code Snippets in a Legacy Language Service for details of these substitution variables.

The class constructor specifies the minimum required parameters. A user-defined attribute class also supports optional named parameters. These named parameters are specified in the constructor's parameter list after the required parameters. All of the properties on this class that support both get and set operators can be specified as a named parameter. The Example shows how named parameters are used.

The following user-defined attributes are used for language services:

Attribute Description
ProvideLanguageServiceAttribute Registers the language service with Visual Studio and specifies what features are supported.
ProvideLanguageExtensionAttribute Associates a file extension with the language service.
ProvideLanguageEditorOptionPageAttribute Specifies a property node or page for the Options dialog box specific to the language service.
ProvideLanguageCodeExpansionAttribute Specifies location information to support code snippets in the language service.
ProvideServiceAttribute Registers a language service as a Visual Studio service. All services supplied in managed code use this attribute.

Notes to Inheritors

This attribute class cannot be inherited from so there is nothing to implement.

Notes to Callers

This attribute class is typically applied to your primary VSPackage class, although it can appear on any class. This attribute should appear only once.


ProvideLanguageCodeExpansionAttribute(Object, String, Int32, String, String)

Initializes a new instance of the ProvideLanguageCodeExpansionAttribute class.



Gets or sets a semicolon-delimited string containing the directory or directories that should be created.


Gets the name of the language.


Gets the GUID of the language service.


Gets or sets a semicolon-delimited string containing the default paths to search for snippets.


Gets or sets whether or not the roots of the code snippets should be shown.


Override the TypeID property in order to let the RegistrationAttribute derived classes to work with System.ComponentModel.TypeDescriptor.GetAttributes(...). An attribute derived from this one will have to override this property only if it needs a better control on the instances that can be applied to a class.

(Inherited from RegistrationAttribute)



Gets the registry path (relative to the registry root of the application) of the VSPackage.

(Inherited from RegistrationAttribute)

Creates all of the registry keys and entries as specified by the class constructor.


Removes all of the registry keys and entries as specified by the class constructor.

Applies to