Where to place global variables in MVVM (Caliburn micro)

Question

I'm refactoring a program done in WinForms to WPF and I'm using Caliburn.Micro as a framework to implement the MVVM pattern.

In the old program, I use a StatisHelper class to allow different static variables like the theme, the language, the username or the rights of access, etc ..

I know that it could be insecure because these variables are public, but I doubt that my end users know how to access these values...

Anyway, I would like to know the best practice in MVVM to save global values (in concrete, I'm using Caliburn.Micro framework) that can be accessed for all the view-models.

Thank you for your responses.

Answer 1

You could use a singleton class (frowned upon by some). Note that the constructor is private, so nothing else can create an instance. Use the Instance property to access it. The Instance property in this example will only construct the singleton object the first time it's accessed.

To use it, simply do something like var foo = Globals.Instance.SomeProperty.

Note that this has nothing to do with WPF or MVVM, and could have been used in WinForms as well.

public class Globals {
    private Globals _Instance;
    public Globals Instance {
        get {
            if (_Instance == null)
                _Instance = new Globals();
            return _Instance;
        }
    }

    private Globals() {
    }

    public string SomeProperty { get; set; }
}