Does target .net Framework matter for DLLs?

[JamesX]

Hi I am new to programming and I just wrote a small test program to see if Visual Studios 2010 works.

It seems that even though I targeted the Program for .Net 3.5, the DLL project is still targeted for 4.0 (with no options to change it, that I found).

The program runes fine on my computer. But it crashes on friend's computers unless they also had .Net 4.0 Installed (comes with VS2010 Beta).

Does it matter that the DLL library is targeted for .net 4.0? Or is the crashes unrelated to the DLL file and is something else at work?

[Edit]
Just tested and it is the DLL's fault. If I comment out all the lines that uses the DLL the program launch without any problems.

Does anyone know how to fix the requirement for .net 4.0 in regards to a DLL? I have no idea how.

[weaknessforcats]

Can't you change the Application property of the DLL project from 4.0 to 3.5 ?

[JamesX]

There is no options to change it that I have found.

The options for targeting framework is grayed out.

Is there a way to change it?

[weaknessforcats]

Are we talking about the same thing?

I created a C# class library project and the Application property does let me set the target framework. Of course, I am using VS.NET 2008 so my choices are 2.0, 3.0 or 3.5.

[JamesX]

The DLL Library project I gotten was a pre-made one. I don't see an option to re-target an existing project. I am complete newbie, so please forgive me if I just missed some glaringly obvious menu option.

I tried both in 2008 and 2010 to no avail.

What makes it even worse is even if you select 2.0 as the project target for Win32 Project, once the DLL project is made it will be targeting 4.0 regardless. That could just be because it is beta however.

[weaknessforcats]

Are you talking about a C/C++ DLL project ot a C# Class Library project?

[JamesX]

a C++ Win32 Project, that is added into a C# Windows Form Application.

It is the MuParser (C++)'s C# Wrapper. The Wrapper is C# but the DLL that came with the project didn't work,so I had to make a new project and build the DLL from scratch.

[weaknessforcats]

There is nothing in a Win32 C/C++ DLL project to set a framework version.

Therefore, if that DLL is calling a framework function, it will use the one that's currently on the system. Like 4.0.

I don't know how your DLL works but I'm guessing that there's no code in there requesting a specific framework version. Prseumable this could be added in the DllMain.

Only in a C# Class Library project can you target a specific framework version.