1. Mark Seemann - Dependency Injection in .NET

2. DI Definition
Dependency Injection is a set of software design principles and patterns that enable us to develop loosely coupled code.
* DI Container is not required.
* Inversion of Control is a wider term than Dependency Injection.

3. Benefits of DI Late binding
Services can be swapped with other services.
Extensibility & Maintainability
Code can be extended and reused in ways not explicitly planned for.
Classes with clearly defined responsibilities are easier to maintain.
Parallel development
Code can be developed in parallel.
Testability
Classes can be unit tested.

4. Stable & Volatile Dependencies
Stable dependency satisfies all these rules:
The class or module already exists.
You expect that new versions won’t contain breaking changes.
The types in question contain deterministic algorithms.
You never expect to have to replace the class or module with another.
If dependency does not satisfy one or several points from above list, then it’s a volatile dependency that should be injected.

5. Configuring DI Containers

6. Configuration ways: pros & cons

7. Composition Root

8. Register Resolve Release

9. DI Patterns Constructor Injection Property Injection Method Injection
Ambient Injection

10. Constructor Injection

11. Property Injection

12. Property Injection usage
Unity DependencyAttribute

13. Method Injection

14. Ambient Context

15. Choosing DI pattern

16. DI anti-pattern: Control Freak

17. DI anti-pattern: Bastard Injection

18. DI anti-pattern: Constrained Construction
*Is only applicable for late binding.

19. DI anti-pattern: Service Locator

20. DI refactorings (challenges)
Mapping runtime value to ABSTRACTIONS
Route algorithm example. Use Abstract Factory.
Working with short-lived DEPENDENCIES
Connections, clients, etc. Use Abstract Factory.
Resolving cyclic DEPENDENCIES
Break dependency through Property Injection.

21. Object Composition Console application ASP.NET MVC application
WCF service
WPF application
ASP.NET application
PowerShell cmdlets

22. Lifestyle catalog

23. Interception

24. Cross-Cutting Concerns

25. DI Container Feature comparison