I have an older asp.net solution consisting of several projects. The data access layer is contained in a separate class library project while the frontend is in another project.
The data access project is using Application Settings (https://msdn.microsoft.com/en-us/library/a65txexh.aspx) for several settings, among others 3 connection strings. I have a /Properties/Settings.settings file which - when changed - results in an updated /app.config file.
My problem is that I haven't found any way to automatically change these settings when building and publishing the solution.
I know about web.config transformations (https://msdn.microsoft.com/en-us/library/dd465318(v=vs.100).aspx) and that Visual Studio offers the ability to create a so called "Config Transform". But as far as I know a class library doesn't have a web.config file and this menu option is not available for neither the Settings.settings file nor the app.config file.
Is there a way to automatically change the settings.settings file/app.config or is there a completely different best practise to provide connections strings to a class library?
EDIT: I should add to the above that the Data Access class library is using Datasets.