.NET: Load two version of the same DLL

Question

I need to load two versions of the same DLL in order to compare their outputs. I assume that I can use AppDomains for this, but I need some guidence.

Answer 1

Check out Activator.CreateInstance() on MSDN. Code samples within.

http://msdn.microsoft.com/en-us/library/ms224132.aspx

Answer 2

Ok, it was actually a lot easier than I imagined.

    m_Assembly1 = Reflection.Assembly.LoadFile(IO.Path.Combine(System.Environment.CurrentDirectory, "Old Version\Some.dll"))
    m_Assembly2 = Reflection.Assembly.LoadFile(IO.Path.Combine(System.Environment.CurrentDirectory, "New Version\Some.dll"))

    Console.WriteLine("Old Version: " & m_Assembly1.GetName.Version.ToString)
    Console.WriteLine("New Version: " & m_Assembly2.GetName.Version.ToString)

    m_OldObject = m_Assembly1.CreateInstance("FullClassName")
    m_NewObject = m_Assembly2.CreateInstance("FullClassName")

From here on out I used late binding and/or reflection to run my tests.

Answer 3

Here is a guide to do that:

extern alias oldVer;
extern alias newVer;

and when you compile:

csc /r:oldVer=Somepath\ClassLibrary.dll /r:newVer=AnotherPath\ClassLibrary.dll program.cs

or in Visual Studio change the "aliases" field in the property tab of your project references