MVVM ViewModel Service Locator Sample

One of common problems in MVVM is to have Service Locator .Here I created simple implementation on service locator pattern. First we will create interface IServiceLocator :

    public interface IServiceLocator
    {
        T GetInstance<T>() where T : IViewModel, new();
    }

And also we have a Service locator class :

    public class ServiceLocator : IServiceLocator
    {
        private IDictionary<object, object> instances;
        private static IServiceLocator locator = new ServiceLocator();

        private ServiceLocator()
        {
            instances = new Dictionary<object, object>();
        }

        public static IServiceLocator Current { get { return locator; } }

        public T GetInstance<T>() where T : IViewModel,new()
        {
            try
            {
                return (T)instances[typeof(T)];
            }
            catch (KeyNotFoundException)
            {
                this.instances.Add(typeof(T), new T());

                return (T)instances[typeof(T)];
            }
        }

        public void RemoveInstance<T>() where T : IViewModel, new()
        {
            try
            {
                this.instances.Remove(typeof(T));
            }
            catch (KeyNotFoundException)
            {
                
            }
        }
    }

We have to use service locator to initialize the view model instance like this :

   public partial class MyView : UserControl
    {
        public MyView()
        {
            InitializeComponent();

            this.DataContext = ServiceLocator.Current.GetInstance<MyViewModel>();
        }
    }

I hope this code helps and waiting for any comments (it is my first Silverlight experience).

References :

1. Stefano Ricciardi Blog