F＃消耗非托管DLL函数

Question

I have a project written in F# and I have to use an unmanaged DLL for part of it. I'm very new to .Net programing, so this is another level of complexity added on top of everything else.

In the unmanaged DLL's documentation they provide samples of how to consume the functions from C#, like so:

using System;
using System.Runtime.InteropServices;

[DllImport("foo.dll")] public static extern Int32 foo_init(
    [MarshalAs(UnmanagedType.AnsiBStr), In()] ref string FOOarg_Handle,
    [MarshalAs(UnmanagedType.AnsiBStr), In()] ref string FOOarg_User, 
    [MarshalAs(UnmanagedType.AnsiBStr), Out()] out string FOOarg_DataOut, 
    [MarshalAs(UnmanagedType.AnsiBStr), Out()] out string FOOarg_ErrOut);

This is pretty ugly in and of itself, but I have no clue how to do this from F#. Wouldn't it be a good idea to just create a C# class, put all the function definitions that wrap the external DLL's functions in there, and call those from F#, instead of calling the unmanaged functions directly from F#?

How else would one go about this? Thanks in advance!

Answer 1

There doesn't appear to be a description of the syntax for extern function declarations either on MSDN or in the spec. But, as far as I can tell, it mirrors the C declarations verbatim, as you can see from these (rather old) examples .

I left feedback on the MSDN page for External Functions suggesting it include explanation and examples of the syntax.