DLL Import Failure

myvraccount · 2014-07-24T13:23:36

I made a DLL in C++, compiled it just fine, imported the DLL and LIB files into a C# project in VS2012, used the System.Runtime.InteropServices, and attached a [DllImport("DllName.dll")] attribute to the function I wanted to test, making sure the function name and data types match correctly and that it is a static extern function, then tried to call the function. Everything compiled fine without any errors, but then when I run it, as soon as it gets to the line that calls the function, it crashes with a DllNotFoundException. I'm assuming that it's trying to load in the DLL automatically just before it needs to use it, right? That's fine, but for some reason it can't find it, even though I placed it in the project and it appears inside VS2012, along with the LIB file. I also tried changing the extension in the DllImport string to be .lib instead of .dll, and I still get the same error. So does anyone know what I did wrong?

For Beginners

Started by myvraccount July 07, 2014 01:32 PM

31 comments, last by myvraccount 9 years, 8 months ago

DvDmanDT

1,951

July 23, 2014 05:07 PM

I may be wrong but I am quite sure that the 64-bit version of .NET has no problem calling 32-bit dlls. This should all be abstracted and marshalled anyway.

You are wrong. It's not that easy and it has nothing to do with .NET, but rather Windows. Perhaps it would have been possible to implement something that would work in the most simple cases, but it's very easy to come up with scenarios that just wouldn't work. :)

Nypyren

12,313

July 24, 2014 02:48 AM

Here's another possible issue: DLLs can rely on even MORE DLLs. Perhaps it's not the DLL that you're putting everywhere that's the problem; perhaps it's one that it depends on.

There are tools like DependencyWalker ( http://www.dependencywalker.com/ ) which can analyze the dependencies. Try investigating that to see if there's anything else unexpectedly missing.

myvraccount

235

Author

July 24, 2014 01:23 PM

Well that's an interesting idea but given the nature of this DLL, I doubt it relies on any other ones. And because it's a professionally made DLL intended to be distributed and used, if it did require any other DLLs, they should have been mentioned in the documentation.

Actually though, since I can use it in C++, I suppose it can't rely on any that I don't have. I'm only unable to use it in C#.

And as I said, when I make my own DLL in C++ and put that into a C# project, I also put the third party DLL there with it.

DLL Import Failure

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

DLL Import Failure

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines