Is there a more painless way to call Win32 from C#?

Question

Every few months I find myself needing to call Win32 from C#. Though I've done it a dozen times, I've usually forgotten the exact machinations, so I poke around the web or old code and figure out what DllImport statements I need, etc.

Am I alone?

Is there a sanctioned "Win32" class that has the requisite declarations for the entire Win32 API? Seems like there ought to be. Maybe I'm missing something.

Worcester

Definitely not alone. +1 – Vanegas

pinvoke.net is great but a single assembly to reference would be so nice... – Warfourd

I definitely don't want a single compiled assembly. The Win32 API is huge. I mean really huge. Dragging around thousands of API declarations just to get the one you want would be a real chore. Better to have the declarations as source code and copy the ones you want. – Councilman

Dragging around? A single referenced assembly that organized the calls into enums, structs and classes would be extraordinarily useful. Especially if it was documented. But, to each his own, I guess. For me, I'll take the assembly. – Vanegas

I agree that it would be nice to have. I can only assume that Microsoft wanted to discourage people--especially those who might not understand all the ramifications--from crossing the inter-op boundary. – Tavish

Answer 1

You may find http://www.pinvoke.net helpful.

Also, for common Win32 functions, you could try the P/Invoke Interop Assistant.

Selfdevotion

PInvoke Interop Assistant can also be used to translate C code straight to the appropriate signatures and functions. – Diatomite

2024 - There's the new C#/Win32 Source Generator project now as well: github.com/microsoft/CsWin32 – Nihi

It should be mentioend that CsWin32, while it has some nice features, does not integrate into a C# project like a typical C# library and requires significant usage of advanced C# features like fixed, pointers and dereferencing, unsafe context, and more. Many magic numbers are not replaced with enums or constant classes, preferring to maintain the classic signature when it isn't necessary. I found this to make my code base much more complicated and ultimately decided to use older libraries. – Roister

Answer 2

There's no sanctioned Win32 class, but http://www.pinvoke.net is a great central resource for these things.

Councilman

Answer 3

This sounds like a great idea for an open source project.

/em puts on thinking cap, and runs of to pinvoke.net

Vanegas

Answer 4

Getting to the correct DllImport statements are easy like everyone is saying, but for ease if use I usually wrap the Win32 functions I need in C# classes and compile into my core helper assembly. So next time I just reference the assembly. So if I need some Win32 function, chances are it is already in my helper lib if not I just add it.

Also I map the return codes to Exceptions rather, i.e. if the HResult is non zero I throw an Exception so my C# apps do not need to know about HResult or return codes ever.

Repent

Answer 5

Check out: http://code.msdn.microsoft.com/WindowsAPICodePack

Garrygarson

Answer 6

You could use Reflector and search for Win32Native. It has a bunch of definitions that you could use for PInvoking.

Knap

Answer 7

Adding latest solution of using the new Source Generator project, C#/Win32: https://github.com/microsoft/CsWin32

Nihi

It should be mentioend that CsWin32, while it has some nice features, does not integrate into a C# project like a typical C# library and requires significant usage of advanced C# features like fixed, pointers and dereferencing, unsafe context, and more. Many magic numbers are not replaced with enums or constant classes, preferring to maintain the classic signature when it isn't necessary. I found this to make my code base much more complicated and ultimately decided to use older libraries. – Roister