Question

I want to call a function from a .NET DLL (coded in C#) from an Inno Setup script.

I have:

1. marked the Register for COM interop option in the project properties,

2. changed the ComVisible setting in the AssemblyInfo.cs file,

3. added these lines to the ISS script:

   [Files] Source: c:\temp\1\MyDLL.dll; Flags: dontcopy 

   [Code] function MyFunction(): string;     external 'MyFunction@files:MyDLL.dll stdcall setuponly'; 

But I still get the following error:

Runtime Error (at -1:0):

Cannot Import dll:C:\DOCUME~1\foo\LOCALS~1\Temp\is-LRL3E.tmp\MyDLL.dll.

What am I doing wrong?

Answer 1

Oops, my bad, it’s been too long since I’ve read pascal! So, if you need to get the value then there are a couple of possibilities:

1. Write the functionality in C/C++ and export the function, that’s definitely supported.
2. Use a Managed C++ dll to shim to your .NET dll, and expose the call as a C interface point (this should work, but it’s getting messy)
3. Use an .exe to store the result of your code in a .INI file or the registry or in a temp file and read the result in the setup code section (this is now properly nasty)

When I last worked with InnoSetup it didn’t support your scenario directly (calling .NET code from setup).