با تشکر از زحمات شما.

یک بهبود جزئی: مطابق Managed Threading Best Practices بهتره از lock this استفاده نشه و از یک شیء object خصوصی استفاده شود.

Use caution when locking on instances, for example lock(this) in C# or SyncLock(Me) in Visual Basic.
If other code in your application, external to the type, takes a lock on the object, deadlocks could occur.

آموزش عالی  برای کسانی که می‌خواهند WPF و الگوی MVVM و CODE FIRST رو باهم یاد بگیرند :

At the core of developing a data-driven WPF application is a thorough knowledge of how to use the MVVM Pattern and Entity Framework. In this course, Building an Enterprise App with WPF, MVVM, and Entity Framework Code First, you will learn the skills you need to create high-quality enterprise applications with WPF. First, you'll learn about typical scenarios like communicating between different ViewModels, detecting model changes, and handling many-to-many relations. Next, you'll learn all about creating a tabbed user interface. Finally, you'll explore implementing optimistic concurrency and styling your application. When you're finished with this course, you will have a deep understanding of WPF, MVVM, and Entity Framework that will help you immensely as you move forward and create your own data-driven enterprise application