Use types of same name & namespace in 2 .NET assemblies

Question

Out of curiosity, I've created 2 assemblies which both have a class (Class1) with the exact same namespace (Library1). I then create another client referencing those 2 assemblies and try to create an instance of Class1.

The compiler, not surprisingly, gives me a compile-error about the ambiguous reference. Is there any way to explicitly specify the type in the assembly I want to use to avoid the ambiguity?

Note: I know this rarely, if ever at all, happens in practice. It's just a question out of curiosity about language feature.

Answer 1

I think you should use an extern alias to wrap the assembly namespaces outside of the Global namespace. Here's how:

1. In the project that references the 2 assemblies, select one of them under References, and in the Properties window change the Aliases value from global to, say, global, Library1a.

2. Do the same for the the other reference, but give it a different alias-- let's go with global, Library1b for our example.

3. Insert extern alias Library1a; and/or extern alias Library1b; as the first 2 lines of any classes that consume the assemblies.

4. When accessing ambiguous members, qualify the namespace with Library1a. or Library1b.. Examples: Library1a.Library1.Class1... Library1b.Library1.Class1...

Answer 2

It happens in practice and is a real pain, the external alias can't always solve the problem. Here's one example of where it's an issue Duplicate Namepsaces.