public class ViewModelLocator {
        public ViewModelLocator() {
            //if (!ViewModelBase.IsInDesignModeStatic)
            CompositionInitializer.SatisfyImports(this);
        }
 
                //If I do not use AllowDefault = true, the Design Time blows up saying it cannot
                //  match the export to the import
        [Import(AllowDefault = true)]
        public OrbitScreenViewModel SomeViewModelInstance { get; set; }
 
        [Import(AllowDefault = true)]
        public LeaseViewModel LeaseViewModel { get; set; }
 
        }
 
    [Export]
    public class OrbitScreenViewModel : ViewModelBase {
        public OrbitScreenViewModel() {
            if (IsInDesignMode) {
                // Code runs in Blend --> create design time data.
            }
            else { //Do runtime things
 
                        }
                 }
 
        }
 
//There is no App.cs or App.xaml because this is a dynamically loaded xap package for App Partioning
<Navigation:DynamicPage xmlns:vm="clr-namespace:DataForms.Locator" x:Class="DataForms.Screen"
        d:DesignWidth="800" d:DesignHeight="700"
        NavigationCacheMode="Enabled"
        Title="Data">
    <Navigation:DynamicPage.Resources>
            <vm:ViewModelLocator x:Key="VMLocator"/>
    </Navigation:DynamicPage.Resources>
    <Grid x:Name="LayoutRoot" DataContext="{Binding Source={StaticResource VMLocator}, Path=SomeViewModelInstance }">
      ...
      <local:SomeUserControl DataContext="{Binding Source={StaticResource VMLocator}, Path=LeaseViewModel }"/ >    </Grid>