MVVM : Share data between ViewModels

Question

How do I share data between multiple ViewModels ?

For example there is a class named Project in application .

    public class Project : ModelB         


        

Answer 1

Singleton will definitely help. To implement, if I had a class named User:

    private static User mInstance;

    private User () //constructor
    {
    }

    public static User Instance
    {
        get
        {
            if (mInstance == null)
                mInstance = new User();
            return mInstance;
        }
    }