Opening 2 years old project in visual studio

General
1

Hi

Recently I switched to windows and I decided that it’s a good opportunity to lean F#. I peaked up the Get Programming with F# book and started reading. One of the project in the book is this one. However when I opened it in Visual Studio 2019 and tried to build it I got the following error:

|Error||Unknown build error, 'Cannot resolve dependency to assembly 'FSharp.Core, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' because it has not been preloaded. When using the ReflectionOnly APIs, dependent assemblies must be pre-loaded or loaded on demand through the ReflectionOnlyAssemblyResolve event.'|MonopolyGui||||

This corresponds directly with one of my fears of .Net programming - It’s too tied up to the specific environment and IDE. I’m not against working in IDE (although I prefer editors like VSCode) - I’m really against requiring an IDE to build the project …

So I have several questions:

  • Is there a relatively easy way to open and build this project?
  • How can I list what F# versions I have installed?
  • I know that you can edit new F# projects in VSCode but I also heard about requiring Visual Studio if you want to build in certain frameworks (like building for android). So if I mainly want to use F# for command line tools and cross platform GUI applications (Avalonia?) will I have to build it on visual studio or can I use VSCode?

Thanks in advance

Haim

2

I can’t speak to Android as I’ve never tried to target it. However, there’s nothing about command-line applications or Avalonia that requires Visual Studio (AFAIK). In order to have a “smooth” time with F# (on any platform), I’d recommend staying away from .NET Framework (if possible) and only using .NET Core (3.x) or .NET 5 (and up). In either case, you’ll want to install the relevant SDKs from here:

As far as checking versions of things, a good starting point is to run the command:

> dotnet --info

from whatever console environment you like to use.

3

Try using NuGet to adding a dependency to FSharp.Core (an older version from before the time that this sample was created). It is a best practice in general to add FSharp.Core as an explicit dependency for this reason, rather than using the version inferred by the currently installed tooling.

4

That’s great to hear

Yup, that was my feeling also :slightly_smiling_face:

ahhhh, this is really helpful, thanks.

I also managed to build the project after I installed a similar Fsharp.Core version from nuget (it doesn’t seem to have 4.4…).

Great, thanks for the info.

5

Thanks, this is what I finally did when I figured out that Fsharp.Core was not the fsharp version on my laptop but a dependency :slightly_smiling_face: (did I mention I’m a newbie?)

6

You can’t have 2 solutions selected :frowning_face:

Thanks @Prash and @pblasucci , both of your answers helped.

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