In C++ I have some code that requires a const char * to be passed in:
void Load(const char *filename)
If I try using String as MSDN seems to suggest:
[DllImport("foo.dll")]
protected static extern void Load(String filename);
I end up getting an exception stating that the call has an unbalanced stack, due to a mismatch between the managed P/Invoke call and the actual C++ function signature.
What would be the appropriate C# function signature I would need to use? I've tried googling for the answer but I'm not coming up with anything.
The solution: It turns out that the reason why I was getting an "unbalanced stack" error was because the test code I was running called for a file that didn't actually exist in the directory. With CallingConvention=cdecl, and the file in the appropriate place, the issue was resolved.
The problem is the calling convention. And while we're at it, you probably need to specify the character set since it may assume Unicode otherwise:
[DllImport("foo.dll", CharSet:=CharSet.Ansi, CallingConvention:=CallingConvention.Cdecl)]
protected static extern void Load(String filename);