Design Patterns in .NET Training

Delegates should have at least 3 years experience in C# development and be familiar with UML Sequence and Class diagrams.

Introduction to Patterns

• What is a design pattern?
• The evolution of design patterns
• Misconceptions about design patterns
• The dangers of becoming ‘pattern happy’
• Distinguishing between patterns, idioms and refactorings
• Using refactorings to introduce patterns incrementally
• Using patterns to create an object oriented architecture

MVC, MVP and MVVM

• Why MVC is the most important pattern in enterprise architecture
• How the pattern is applied in web frameworks like ASP .NET MVC
• Guidelines for applying MVC successfully in your own designs
• Why Microsoft evolved MVP and MVVM out of conventional MVC
• How MVVM is used in WPF and Windows 10 user interfaces

The Little Language Pattern

• Understanding Little Language and Domain Specific Languages
• Support for DSL’s in .NET via CodeDom and T4 Templates
• LINQ as an example of an Internal DSL

The Observer Pattern

• The disconnect between OO design and event handling
• How the Observer pattern enables event-driven OO code
• The classical implementation of Observer using interfaces
• The .NET (and Delphi) version of Observer using delegates

The Iterator Pattern

• Accessing an aggregate object without knowing its representation
• How Iterator is used in the C++ , Java and .NET collection libraries
• Adding iterator support to your own C# collection classes

The Singleton Pattern

• Why ensure a class only has a single instance?
• Singleton objects verses static utility classes
• The classical implementation of the Singleton pattern
• Language specific solutions to Singleton in C# and Scala
• Making Singletons safe and efficient in concurrent code
• Problems with the double checked locking idiom

Patterns Relating to Factories

• Advantages of separating clients from object creation
• Comparing the Factory Method and Abstract Factory Patterns
• Using Abstract Factory to conceal providers in ADO .NET
• Extending the Factory Pattern into Dependency Injection
• Examples of Dependency Injection Tools for .NET

The Strategy Pattern

• Creating class hierarchies to represent algorithms
• Separating a class from a changing or complex algorithm
• How Strategy is used with Layout Managers in WPF
• How Strategy is used within mocking tools like Moq

The Command Pattern

• Similarities between Srategy and Command
• Using Command objects to simplfy event dispatching
• Incrementally refactoring code to introduce Command
• Uses of the Command Pattern in Web Frameworks

The Proxy Pattern

• Adding services by intercepting messages
• Dynamically creating proxy classes via Reflection
• How proxies can be used for Aspect Oriented Programming
• The interception framework provided with .NET

The Template Method Pattern

• Using polymorphism to customize algorithms
• Similarities between Template and Factory Method

The Decorator and Adapter Patterns

• Using composition to layer extra functionality
• Applying Decorator to create specialized collections
• Distinguishing between Adapter and Decorator
• Uses of these patterns in the .NET I/O libraries

Visitor

• Simplifying class design by modelling operations as visitors
• Adding support for Visitor to existing collections of objects
• Using Visitor to add reporting and logging behaviour
• Code generation in C# with Visitor and the CodeDOM library
• Using Visitor in the design of a C# mock objects generator

The State Pattern

• Benefits of the State Pattern over subclassing
• Modelling objects with complex internal state transitions
• Different approaches to implementing state transitions
• Automatically generating state machines

Parallel Programming Patterns

• Introducing the .NET Parallel Patterns
• Working with thread pools and IOU’s
• The async/await keywords