c# - Using multiple versions of the same DLL

Question

I've been tasked in creating a new module for an application, and so, I'm adding new DLLs to the project. This is all fine and well.

However, in my DLLs I'd like to use a new version of an external DLL (over which I have no control). If I just reference the new DLL and work with that one only, my code will work, but the old code will stop functioning.

Could not load file or assembly 'itextsharp, Version=5.0.6.0, Culture=neutral,
PublicKeyToken=8354ae6d2174ddca' or one of its dependencies. The located assembly's
manifest definition does not match the assembly reference. (Exception from HRESULT:
0x80131040)

I've tried a simple trick of changing the DLLs name, but that apparently was a bit too naive of me, to think it would work. I've tried using the external aliases (by defining them in my references), but I still don't know how to get two files with the same name into one BIN folder...

What should I do?

question from:https://stackoverflow.com/questions/5916855/using-multiple-versions-of-the-same-dll

Answer 1

You can load another version into a specific AppDomain

Possibly too detailed, but here is an article that demonstrates the use of AppDomains in a useful setting and how they work:

http://msdn.microsoft.com/en-us/magazine/cc164072.aspx

In a very basic sense it comes down to this sample code:

    AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
    ...

    static System.Reflection.Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
    {
        if (/*some condition*/)
            return Assembly.LoadFrom("DifferentDllFolder\differentVersion.dll");
        else
            return Assembly.LoadFrom("");
    }