Environment.SpecialFolderPath vs .NET Settings (& resolving environment variables in textbox binding)

Question

I'm a C# noob, and I've been looking for info on best practices for C# application development.

I want to have an application setting that defines where the application will write its log files & reporting output. I want this to default to %USERPROFILE%\Documents\<Vendor>\<Tool>, since these files are created for the user to actually look at and dispose of at their leisure. But, if the user wants the files to be written to some other location, I want to persist their preferences.

My research so far indicates that:

1. It's not generally a good idea to use environment variables directly. Instead, it's recommended to use the Environment.GetFolderPath method and the Environment.SpecialFolders enum to get access to special locations in Windows like the user profile.
2. But, it's recommended to use user-scope .NET Application Settings to persist settings from one session to another.

Is there any good way to reconcile best practice 1 and best practice 2? Is it actually possible to store this default location in the Application Settings in a compatible way without referencing the %USERPROFILE% environment variable?

A related question: Assume I keep %USERPROFILE%\Documents\<vendor>\<tool> as the default value for the Setting. I want the Setting's value to be bound to a textbox on the main application form (with a Browse button to select a new path). How can I bind the Setting to a textbox in such a way that %USERPROFILE% is resolved to a conventional filesystem path (eg C:\Users\<username>\Documents\<vendor>\<tool>) for purposes of display to the user?

Answer 1

I think that storing paths with environment variables is actually the best way to reference a special folder as a string and still make the path easily editable by the user, should s/he decide to do so.

Environment variables can be resolved to a simple string in .NET by calling the Environment.ExpandEnvironmentVariables method. You can use this method just before presenting the path in your TextBox and thus make it easily editable for the user. Once the user customizes the path, you can store it as an absolute path from there on, I suppose.