Adding unmanged code to VB.NET

[Nanda1605]

Hi, I am trying to add a 3rd party dll(C++) to my application which is created on vb.net. when i tried to add that dll as reference i got a error as "A reference to could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component." When i checked this in online, it seems to be unmanged code which is not accepted by .net and also they said P/Invoke command something like that. But actually i dont know how to register a dll or use Pinvoke method or how i add a unmanged dll into my application, Can anyone help in this.

Thanks, Nanda

[Lost User]

Register a dll using regsvr32.exe. Do you know the functions exported by the dll?

[Nanda1605]

Thanks JZ, But again. how to do that with regsrv32.exe, for example my dll name is nanda.dll, where i have to do this and how and what was the output

Thanks, Nanda

[Dave Kreskowiak]

REGSVR32 filename.dll

But, if the .DLL is not COM-based, this wont work and you'll be forced to use P/Invoke to call the functions in the .DLL. You will not be able to set a reference to it and have VS import the functions for you.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[Nanda1605]

Thanks Dave, I tried but It throws a message box <dll> was loaded, but the DllRegisterServer entry point was not found. This file can not be registered. I hope this dll is not com based Can you please help me how to use P/Invoke with an example.

Thanks, Nanda

[Dave Kreskowiak]

You got that error because the .DLL is not COM-based. You'll have to use P/Invoke to get at the functions in that library. I hope you have the documentation on it. http://www.pinvoke.net[^] has tons of examples.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008