Member access call does not compile but static call does

Question

So today I faced interesting problem while trying to build our company solution and I wanted to ask you guys do you know why is this happening. I've been told that it might be from my machine/visual studio because other people did not have same problem.

So we have a method in project A:

private static string RpcRoutingKeyNamingConvention(Type messageType, ITypeNameSerializer typeNameSerializer)
{
   string queueName = typeNameSerializer.Serialize(messageType);

   return messageType.GetAttribute<GlobalRPCRequest>() != null || AvailabilityZone == null
        ? queueName
        : queueName + "_" + AvailabilityZone;
}

where GetAttribute<GlobalRPCRequest>() is defined in public static class ReflectionHelpers

 public static TAttribute GetAttribute<TAttribute>(this Type type) where TAttribute : Attribute;

then we have project B which have method:

public static string GetAttribute(this XElement node, string name)
{
   var xa = node.Attribute(name);
   return xa != null ? xa.Value : "";
}

I have to point out that we have reference to project B in project A. Now what happens is that when I try to build I get compile error:

Error 966 The type 'System.Xml.Linq.XElement' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Xml.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. D:\Repositories\website\website\submodules\core\src\A\Extensions\Extensions.cs 37 13 A

Whats happening is that compiler thinks that I am actually using GetAttribute method from project B(in my opinion!). Why this is happening? Since when I try to navigate to GetAttribute VS leads me to the right method (the one that is in ReflectionHelpers). Could it be because of the reflection? NOTE: I fixed this issue by calling the method statically or adding reference to System.Xml.Linq in my project A, but I am curious of the strange behavior of VS/syntax-checking feature.

Answer 1

It's a guess, but I think your function:

private static string RpcRoutingKeyNamingConvention(Type messageType, ITypeNameSerializer typeNameSerializer) does not match your helper method signature because you try returning a string:

public static TAttribute GetAttribute<TAttribute>(this Type type) where TAttribute : Attribute; which expects a TAttribute return type.

Maybe, you can try modifiying your function RpcRoutingKeyNamingConvention to return GlobalRPCRequest and check if the compiler continues to go crazy.

Answer 2

Visual Studio gets confused all the times! I tried to reproduce the scenario in my VS 2015 (.NET 4.6) and it compiles just fine. I didn't have to add reference to System.Xml.Linq in my Project A.

My guess is that it might be a cache issue. You might want to try this:

1. Remove reference to Project B
2. Clean then rebuild both solutions
3. Add the reference back
4. Rebuild and voila!! Well.. hopefully

Hope it helps, let me know :)