我添加了一个项目作为参考，但仍然找不到

Question

I'm using VS10 and C# and I've encountered a weird problem. I have 2 project A and B, A is a class library, and B is a console project. B depends on A, so I added the project reference of A to B.

But when I use types created in project A in project B, VS complains the following:

The type or namespace name could not be found (are you missing a using directive or an assembly reference?)

I've never encountered this problem before, does anyone know what went wrong?

Thanks.

Answer 1

Since you have Project B targetting Client Profile while the library is built for 4.0 this cannot be done.

You will have to upgrade the console app to target 4.0

MSDN

If you are targeting the .NET Framework 4 Client Profile, you cannot reference an assembly that is not in the .NET Framework 4 Client Profile. Instead you must target the .NET Framework 4.

Answer 2

There might be one of these reasion.

1. your using namespace statement is not point the locaiton which is
   using the class in B project.
2. your you classA in project a is not
   accessible from the project b so make them public.
3. you are pointing diffrent profile of dotnet framework.
4. your dll of project a is not readable by project b. cross check the refrance.