1. © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel www.sela.co.il

2.  MVVM  MEF  MVVM + MEF  Layers © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 2

3.  Cleanly separate visual from business  Developers focus on logic  Designers focus on visual  Unit test independently © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 3 Model C# Model C# ViewModel C# ViewModel C# View XAML View XAML Data Binding

4.  Library for creating lightweight, extensible applications  Discover and use extensions with no configuration  Easily encapsulate code and avoid fragile hard dependencies © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 4 Part A (export) Part A (export) Import Container Compose Catalog Part B (export) Part B (export) Part C (export) Part C (export)

5. Combining MEF with MVVM Combining MEF with MVVM – Loosely coupled view components – Easy testing with Mocks and Stubs – Complex view Blendability © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 5 View Import Container Compose Catalog Model (export) Model (export) ViewModel (export) ViewModel (export)

6. Comprises business entities Comprises business entities – Services (Thin client) – Models (Rich client) Lower layer Lower layer – No references to upper layers – No references to WPF! – C#/VB.NET © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 6

7. 7 LEGO.net Business Layer

8. Comprises application logic Comprises application logic – View Models – Workflow Controllers Middle layer Middle layer – No references to upper layers – No references to Visuals (PresentationFrameowrk) – C#/VB.NET © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 8

9. 9 LEGO.net Application Layer

10. Comprises presentation logic Comprises presentation logic – Views (User Controls, Data Templates) – Attached Behaviors – Visual Trees Upper layer Upper layer – XAML © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 10

11. © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 11 LEGO.net Presentation Layer

12. 12 © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel

13. 13 MVVM Cleanly separate visual from business MEF is a Library for creating lightweight, extensible applications MVVM + MEF = Extensible client UI, comprises reusable loosely coupled parts, easy to test, design and maintain

14. © Copyright SELA software & Education Labs Ltd. 14-18 Baruch Hirsch St.Bnei Brak 51202 Israel 14 Thank You!