MVVM Light and EF 6

After a few years of experiencewith the EntityFramework, the time has come tostart studyingMVVM usingMVVM Light. I developeda small application thatwill perform the classicCRUD operations,and throughEF 6I created the"Model".

<Window x:Class="MvvmLightEf.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:ignore="http://www.ignore.com"
        mc:Ignorable="d ignore"
        Height="480"
        Width="640"
        Title="MVVM Light Application"
        DataContext="{Binding Main, Source={StaticResource Locator}}" WindowStartupLocation="CenterScreen"><Window.Resources><ResourceDictionary><ResourceDictionary.MergedDictionaries><ResourceDictionary Source="Skins/MainSkin.xaml" /></ResourceDictionary.MergedDictionaries></ResourceDictionary></Window.Resources><Grid x:Name="LayoutRoot"><Grid.RowDefinitions><RowDefinition Height="34*"/><RowDefinition Height="415*"/></Grid.RowDefinitions><TextBlock FontSize="36"
                   FontWeight="Bold"
                   Foreground="Purple"
                   Text="{Binding WelcomeTitle}"
                   VerticalAlignment="Center"
                   HorizontalAlignment="Center"
                   TextWrapping="Wrap" Margin="316,160,316,207" Grid.Row="1" Height="48" Width="0" /><StackPanel Orientation="Horizontal" Grid.Row="0"><Button Content="New" Height="23" Name="btnNew" Width="75" Command="{Binding NewCommand}" /><Button Content="Search" Height="23" Name="btnSearch" Width="75" Command="{Binding SearchCommand}" /><Button Content="Delete" Height="23" Name="btnDelete" Width="75" Command="{Binding DeleteCommand}" /><Button Content="Save" Height="23" Name="btnSave" Width="75" Command="{Binding SaveCommand}" /><Button Content="Exit" Height="23" Name="btnExit" Width="75" Command="{Binding ExitCommand}" /></StackPanel><TextBox HorizontalAlignment="Left" Height="24" Margin="181,102,0,0" Grid.Row="1" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="50"/><TextBox HorizontalAlignment="Left" Height="24" Margin="181,131,0,0" Grid.Row="1" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="150"/><TextBox HorizontalAlignment="Left" Height="24" Margin="181,160,0,0" Grid.Row="1" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="150"/><Label Content="ID" HorizontalAlignment="Left" Margin="116,102,0,0" Grid.Row="1" VerticalAlignment="Top" Height="24" Width="51"/><Label Content="Name" HorizontalAlignment="Left" Margin="116,131,0,0" Grid.Row="1" VerticalAlignment="Top" Height="24" Width="51"/><Label Content="Surname" HorizontalAlignment="Left" Margin="116,160,0,0" Grid.Row="1" VerticalAlignment="Top" Height="24" Width="60"/></Grid></Window>

Customer.cs:

namespace MvvmLightEf.Model
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data.Entity.Spatial;

    [Table("Customer")]
    public partial class Customer
    {
        public int ID { get; set; }

        [StringLength(50)]
        public string Name { get; set; }

        [StringLength(50)]
        public string Surname { get; set; }
    }
}

MyContext.cs:

public partial class MyContext : DbContext
    {
        public MyContext()
            : base("name=MyContext")
        {
        }

        public virtual DbSet<Customer> Customers { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
        }
    }

ViewModelLocator.cs:

public class ViewModelLocator
    {
        private static MainViewModel _main;

        /// <summary>
        /// Initializes a new instance of the ViewModelLocator class.
        /// </summary>
        public ViewModelLocator()
        {
            ////if (ViewModelBase.IsInDesignModeStatic)
            ////{
            ////    // Create design time view models
            ////}
            ////else
            ////{
            ////    // Create run time view models
            ////}

            CreateMain();
        }

        /// <summary>
        /// Gets the Main property.
        /// </summary>
        public static MainViewModel MainStatic
        {
            get
            {
                if (_main == null)
                {
                    CreateMain();
                }

                return _main;
            }
        }

        /// <summary>
        /// Gets the Main property.
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance","CA1822:MarkMembersAsStatic",
            Justification = "This non-static member is needed for data binding purposes.")]
        public MainViewModel Main
        {
            get
            {
                return MainStatic;
            }
        }

        /// <summary>
        /// Provides a deterministic way to delete the Main property.
        /// </summary>
        public static void ClearMain()
        {
            _main.Cleanup();
            _main = null;
        }

        /// <summary>
        /// Provides a deterministic way to create the Main property.
        /// </summary>
        public static void CreateMain()
        {
            if (_main == null)
            {
                _main = new MainViewModel();
            }
        }

        /// <summary>
        /// Cleans up all the resources.
        /// </summary>
        public static void Cleanup()
        {
            ClearMain();
        }
    }

MainViewModel.cs:

public class MainViewModel : ViewModelBase
    {
        private readonly MyContext ctx;

        private RelayCommand saveCommand;
        private RelayCommand exitCommand;

        public ICommand SaveCommand
        {
            get
            {
                if (saveCommand == null)
                    saveCommand = new RelayCommand(() => Save());
                return saveCommand;
            }
        }
        public ICommand ExitCommand
        {
            get
            {
                if (exitCommand == null)
                    exitCommand = new RelayCommand(() => Exit());
                return exitCommand;
            }
        }

        private void Save()
        {
            throw new System.NotImplementedException();
        }
        
        private void Exit()
        {
            Application.Current.Shutdown();
        }

        /// <summary>
        /// Initializes a new instance of the MainViewModel class.
        /// </summary>
        public MainViewModel()
        {
            if (IsInDesignMode)
            {
                // Code runs in Blend --> create design time data.
            }
            else
            {
                // Code runs "for real"
                ctx = new MyContext();
            }
        }

        public override void Cleanup()
        {
            // Clean up if needed
            base.Cleanup();
        }
    }

Now thequestions: withEF, I have alwaysused a GenericRepository together withUoW.

namespace DAL
{
    public class GenericRepository<T> : IGenericRepository<T> where T : class, new()
    {
        private MyContext ctx;
        private readonly DbSet<T> dbSet;
        public GenericRepository(MyContext context)
        {
            ctx = context;
            dbSet = ctx.Set<T>();

            ctx.Configuration.LazyLoadingEnabled = false;
            ctx.Configuration.ProxyCreationEnabled = false;
        }
        public T Find(int id)
        {
            return dbSet.Find(id);
        }

        public void Insert(T entity)
        {
            dbSet.Add(entity);
        }

InMVVMthe RepositoryandtheUoWwhereI placethem?

private IUnitOfWork uow;
private Customer entity;

private void RDB_Save()
        {
            using (uow = new UnitOfWork())
            {
                entity = new Town()
                {
                    Name= nameTextBox.Text,
                    Surname = surnameTextBox.Text,
                };
                uow.Customer.Insert(entity);
                uow.Save();
            }
        }