<bindingRedirect> Element

Redirects one assembly version to another.

<configuration>
   <runtime>
      <assemblyBinding>
         <dependentAssembly>
            <bindingRedirect>

<bindingRedirect 
   oldVersion="old assembly version"
   newVersion="new assembly version"/>

Required Attributes

Attribute	Description
oldVersion	Specifies the version of the assembly that was originally requested. The format of an assembly version number is major.minor.build.revision. Valid values for each part of this version number are 0 to 65535. You can also specify a range of versions in the following format: n.n.n.n - n.n.n.n
newVersion	Specifies the version of the assembly to use instead of the originally requested version in the format: n.n.n.n

Remarks

When you build a .NET Framework application against a strong-named assembly, the application uses that version of the assembly at run time by default, even if a new version is available. However, you can configure the application to run against a newer version of the assembly. For details on how the runtime uses these files to determine which assembly version to use, see How the Runtime Locates Assemblies.

You can redirect more than one assembly version by including multiple <bindingRedirect> elements in a <dependentAssembly> element.

Explicit assembly binding redirection in an application configuration file requires a security permission. This applies to redirection of .NET Framework assemblies and assemblies from third parties. The permission is granted by setting the BindingRedirects flag on the SecurityPermission Class. For more information, see Assembly Binding Redirection Security Permission.

Example

The following example shows how to redirect one assembly version to another.

<configuration>
   <runtime>
      <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
         <dependentAssembly>
            <assemblyIdentity name="myAssembly"
                              publicKeyToken="32ab4ba45e0a69a1"
                              culture="neutral" />
            <bindingRedirect oldVersion="1.0.0.0"
                             newVersion="2.0.0.0"/>
         </dependentAssembly>
      </assemblyBinding>
   </runtime>
</configuration>

Configuration File

This element can be used in the application configuration file, machine configuration file (machine.config), and the publisher policy file.

See Also

Runtime Settings Schema | Configuration File Schema | Redirecting Assembly Versions