Upgrade a reference dll in a C# project without recompiling the project

Jeff Lundstrom picture Jeff Lundstrom · Sep 22, 2009 · Viewed 9.2k times · Source

I need to take a built version of an C# application and change one of the reference dll's. What is the best way to do this, I have specific version turned off on the reference dll but as soon as I test replacing the dll with a newer version, I get the "Could not load file or assembly XXXXX, Version=XXXXX. Is there a way to stop the loader from caring about the version of the dll so the dll will just attempt to load?

Answer

Jeff Sternal picture Jeff Sternal · Sep 22, 2009

Yes, you can do this - see the MSDN article Redirecting Assembly Versions.

You should read the whole document, but it essentially involves either the assembly's publisher creating a 'publisher policy file' or the consumer adding a bindingRedirect to an app.config file, like this (copied directly from the article):

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

A few notes:

  • If you haven't explicitly specified your culture (as many don't), it will be "neutral" rather than "en-us".

  • If you don't already know it, you can get the assembly's public key token using the strong name utility, like this: sn -t [AssemblyPath]