Reference 2 dlls using the same namespace in vb.ne

Question

I have a vb.net 3.5 class library project that needs to reference two assemblies that have the same namespace. We have two third party dll's in which one is version 5.1 and the other is version 6.1. They have the same dll filename and they utilize the same namespace and functions/class names. The project needs to use one or the other depending on a specific situation.

I've investigated up on a c# process that uses the "extern alias" feature to pull in the different assemblies.

http://blogs.msdn.com/b/ansonh/archive/2006/09/27/774692.aspx

What use is the Aliases property of assembly references in Visual Studio 8

It seems that this feature isn't fully available for vb.net.

Things I've Tried

I've renamed the 2nd dll and added both references to my project. At this point I get tons of: 'blah' is ambiguous in the namespace.

So I need to alias the different versions. In vb.net you can do aliases on an imports statement like:

Imports version5 = Somedll.Something

The problem is I can't setup an assembly reference alias for the different versions of the dll. Apparently in vb.net you can't set these up in the reference properties window. So I tried setting them in in my project file like this:

<Reference Include="somedll.5.Navigation">
  <HintPath>..\..\Utility\ThirdPartyDLLS\somedll.5.dll</HintPath>
      <Aliases>SomeDLL5</Aliases>
      <Private>False</Private>
</Reference>
<Reference Include="somedll.6.Navigation, Version=6.1.0.0, Culture=neutral, PublicKeyToken=6d02be8724ca751c, processorArchitecture=MSIL">
  <SpecificVersion>False</SpecificVersion>
  <HintPath>..\..\Utility\ThirdPartyDLLS\somedll.6.dll</HintPath>
      <Aliases>SomeDLL6</Aliases>
      <Private>False</Private>
</Reference>

I would then expect this to work:

Imports version5 = SomeDLL5.Something
Imports version6 = SomeDLL6.Something

But the "SomeDLL5/6" doesn't show up in intellisense. So how can I reference both dll's in the same project?

Answer 1

I'm the VB spec lead. I'm afraid that there's no VB way of doing this (short of reflection, as DaMartyr said). I know this is a drag. I'll put it on the agenda for our next VB Language Design Meeting.

Answer 2

Does this help? "In the rare event that you reference 2 assemblies which have the same type names and the same namespaces (such as 2 different versions of the same dll) - you can distinguish which assembly to use for a given type using an alias. The default alias for all references is global, but you can specify your own alias for any assembly when you reference it (using a compiler switch - or just use the properties box in Visual Studio) - and have an extern alias clause at the top of your code file where you use it - you would access the types from different assemblies with ::MyNamespace.Type"

Source: two different DLL with same namespace

Answer 3

Try the System.Reflection Namespace if you can take the performance hit.