Question

I am using WritePrivateProfileString in c# (through DllImport) to store paths taken from textboxes on the interface. And the .ini file name is hardcoded in my application

string ini_file = ".\\config.ini";

However, when the file writing happens, the configuration file is written to the first path taken from the interface instead of writing it to the exe directory. Which is quite odd.
Debugging shows that the values are sent correctly to the WritePrivateProfileString but it still is written to the wrong location. Anyone knows why is that happenening?

Answer 1

I’d guess that something is changing the working directory of your process, most likely your code in the process. Note that the documentation has this to say:

If the lpFileName parameter does not contain a full path and file name for the file, WritePrivateProfileString searches the Windows directory for the file. If the file does not exist, this function creates the file in the Windows directory.

Now my guess is that this applies if you supply just a file name. Because your file name starts with . I believe that will force the function to start from the current working directory.

Having said all of that, and no matter what the cause of the problem is, you should use a fully-qualified path in order to make sure the file is written where you want it to be written. Whenever you want the file to go in a specific directory, it’s always easiest to force that by using fully-qualified paths.

You can find the path to your executable using Application.ExecutablePath and then remove the file name part.

Another point to make is that the same directory as the executable may be a bad choice. If your program is installed under the Program Files directory then the directory which contains the executable will not be generally writeable. I think you should consider using a directory under in the user profile. Look for one of the Environment.SpecialFolder values.