add Element for assemblies for compilation (ASP.NET Settings Schema) 

Adds an assembly reference to the collection.

             [,Version=version number] 

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.


Attribute Description


Required String attribute.

Specifies a comma-separated assembly combination consisting of version, culture, and public key tokens. ASP.NET searches for the assembly DLL first in the private Bin directory for the application, and then in the system assembly cache.

Child Elements


Parent Elements

Element Description


The root element in every configuration file that is used by the common language runtime and the .NET Framework applications.


Specifies the root element for the ASP.NET configuration section.


Configures all compilation settings that ASP.NET uses to compile applications.


Defines a collection of names of assemblies that are used during compilation of an ASP.NET application.


The add element adds an assembly reference to use during compilation of a dynamic resource. ASP.NET automatically links this assembly to the resource when compiling each code module.

The value of the add element is an assembly name, not a DLL path. ASP.NET looks up the assembly name to find its physical DLL location. Optionally, you can specify the asterisk (*) wildcard character to add every assembly within the private assembly cache for the application, which is located either in the \bin subdirectory of an application or in the.NET Framework installation directory (%systemroot%\Microsoft.NET\Framework\version\). For detailed information, see Load.

Default Configuration

The following default assemblies element is configured in the root Web.config file.

    <add assembly="mscorlib" />
    <add assembly="System, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <add assembly="System.Configuration, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="System.Web, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="System.Data, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <add assembly="System.Web.Services, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="System.Xml, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <add assembly="System.Drawing, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="System.EnterpriseServices, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="System.Web.Mobile, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <add assembly="*" />


The following code example demonstrates how to add an assembly reference to an application.

            <add assembly="System.Data, Version=1.0.2411.0, 

Element Information

Configuration section handler


Configuration member


Configurable locations


Root-level Web.config

Application-level Web.config

Virtual or physical directory–level Web.config


Microsoft Internet Information Services (IIS) version 5.0, 5.1, or 6.0

The .NET Framework version 1.0, 1.1, or 2.0

Microsoft Visual Studio 2003 or Visual Studio 2005

See Also


How to: Configure Specific Directories Using Location Settings
How to: Lock ASP.NET Configuration Settings


assemblies Element for compilation (ASP.NET Settings Schema)
clear Element for assemblies for compilation (ASP.NET Settings Schema)
remove Element for assemblies for compilation (ASP.NET Settings Schema)
configuration Element (General Settings Schema)
system.web Element (ASP.NET Settings Schema)
compilation Element (ASP.NET Settings Schema)


ASP.NET Compilation Model
ASP.NET Web Page Code Model
ASP.NET Web Site Precompilation Overview
ASP.NET Configuration File Hierarchy and Inheritance
Securing ASP.NET Configuration
ASP.NET Configuration Scenarios

Other Resources

General Configuration Settings (ASP.NET)
ASP.NET Configuration Settings
Configuring ASP.NET Applications
ASP.NET Configuration Files
ASP.NET Configuration API