Use VB.NET and C# in the same application?

Question

I am developing a GUI based application in MS Visual Studio 2005, I just want to know if it is possible to use both VB.NET and C# in the same project. Or can I include a module written in C# in my VB.NET project?

I have a class written in C# which I want to use in my VB.NET based project, so if I can include and call functions from that project than I won't have to write the class again in VB.NET.

So please help me as I am new to .NET programming.

Answer 1

I just want to know that is it possible to use both VB and C# in the same project.

No, not in the same project . On the other hand, you can use them in the same solution .

Or can i include a module written in C# in my VB.net project.

I propose that you create a solution containing two projects: one in C# which forms a library that you use from your VB project. This is straightforward, easy to maintain and easy to extend.

Answer 2

I've never done it myself, but I know you can compile the C# code into a dll and then load and reference the dll in your VB project.

From "Calling C# class in VB.net" :

I think the C# code that you want to use must be compiled as a DLL. Once that is done, simple add a reference to that project to your VB.Net project, import the namespace you need, and then you can use the C# code.

Also see How To: Create and Use C# DLLs (from MSDN, for VS2005)

Answer 3

You also want to ensure that you C# code is CLS compliant. This means that it won't publicly expose any functionality which other .NET languages won't understand (for example unsigned ints - which don't exist in VB, or differing classes only by case - since VB is not case-sensitive). To do this you need to add an attribute so that the compiler will raise errors if you have broken any of the guidelines. This article shows you how to do this:

The CLSCompliantAttribute can be applied to assemblies, modules, types, and members.

For marking an entire assembly as CLS compliant the following syntax is used

 using System; [assembly:CLSCompliant(true)] 

For marking a particular method as CLS compliant the following syntax is used

 [CLSCompliant(true)] public void MyMethod()` 

Answer 4

Put VB.NET and C# code in separate projects. (I am using both VB.NET and C# in my open source project, http://msquant.sourceforge.net/ , and it works great).

You don't need to worry about DLLs, just reference the project (use tab "Project" in the "Add Reference" dialog box). Eg if you need to use a function in the C# code/project add a reference in the VB.NET project to the C# project.

Answer 5

You can't use a C# file and VB file in the same project. You can, however, have VB and C# projects in the same solution and reference them.

In your code you can use:

Imports namespace 

or

using namespace

Once the reference has been added to the appropriate project build the solution and you are good to go.

You can also create a VB.NET Library in a separate solution, compile it and import the DLL into the C# Project or vice versa.

Answer 6

You must also know that if you have a VB.NET project with a C# project in the same solution with one of them having a reference to the other, changes apply in the referencing project will just be available to the other after rebuilding the solution. It's like having binary reference, but with the capability to change code on the same solution.

Personally, I don't like this, but I'm always in the situation where I modify the code in the referencing project and don't know why my changes are not in the code where I use it and I figure it out, oohhhh, I must rebuild.

For temporary help, it could be acceptable but not for programming every day.

Answer 7

If you were only planning on using the module in Visual Basic projects, then you should consider just converting the code to Visual Basic. If you need to use the module in both C# and VB.NET programs I would use one of the solutions posted above

You might try something like * Convert C# to VB.NET . It converts C# to VB.NET code. I use this page exclusively when I have to convert something I find on the net that was written in C#.