Externalize config (password, connectionString) in UWP - config

Question

I'm looking for a way to externalize some config in an UWP application.
The application need to connect to an Alfresco Server. And I want the user to be able to configure the Login, Password, and the url of the server.
I tried to put an xml file in my assets file, but when the App is installed, it's locate in C:\Program Files\WindowsApps, and the user can't have an easy access to it.
Is there any way to acheiev this like with an app.config file ?

Answer 1

A possibility is to use a known StorageFolder like :
KnownFolders.DocumentsLibrary
If you add a file type association into you manifest (Package.appxmanifest > Declarations > File Type Associations) for a particular extension (like .config), your app can read files of this type in the document folder. Users can edit theses files manualy too.
Note all files you include in your assets (in your package) are read-only files.
Another way if your users are experienced : they can edit a file in the local storage (with no need to make a file association into your manifest). In this case, you use the following StorageFolder :
ApplicationData.Current.LocalFolder
And users can edit files into a specifique directory :
C:\Users\<UserName>\AppData\Local\Packages\<AppId>\AppData

Answer 2

I had a very similar issue where I needed to use an external file that is not tracked by source control. There are two ways to access data from resource or configuration files.
One is to open and parse a configuration file. Given a file sample.txt with Build Action Content (Copy to Output Directory doesn't matter), we can read it with
var uri = new System.Uri("ms-appx:///sample.txt");
var sampleFile = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(uri);
or
var packageFolder = Windows.ApplicationModel.Package.Current.InstalledLocation;
var sampleFile = await packageFolder.GetFileAsync("sample.txt");
followed by
var contents = await Windows.Storage.FileIO.ReadTextAsync(sampleFile);
Alternatively, we can use Resources. Add a new Resource item to the project, called resourcesFile.resw. To access data, use:
var resources = new Windows.ApplicationModel.Resources.ResourceLoader("resourcesFile");
var token = resources.GetString("secret");
I wrote more verbose answer in a blog post Custom resource files in UWP