Method binding to base method in external library can't handle new virtual methods “between”

Question

Lets say I have a library, version 1.0.0, with the following contents:

public class Class1
{
    public virtual void Test()
    {
        Console.WriteLine( \"Li         


        

Answer 1

When I build the executable with the first version of the library (I named mine "Thing"), and disassemble it I get:

L_000d: call instance void [Thing]Thing.Class1::Test()

Rebuilding it with the new DLL referenced:

L_000d: call instance void [Thing]Thing.Class2::Test()

So that confirms the decision to which method is referred to is made compile-time.

Answer 2

This was the subject of my blog on March 29th:

http://blogs.msdn.com/ericlippert/archive/2010/03/29/putting-a-base-in-the-middle.aspx

Turns out that C# 1.0 did it your way, and that this decision causes some interesting crashes and performance problems. We switched it to do it the new way in C# 2.0.

I learned a lot from this question. See the blog for details.