Design Patterns in C# (.NET)

The book "Design Patterns in C# (.NET)" is a practical guide for .NET developers seeking to master fundamental and advanced design patterns. Unlike abstract theoretical materials, this book focuses on real-world use cases of patterns within the .NET Core and .NET Framework ecosystem.

What this book is about

The book covers all 23 classic GoF (Gang of Four) patterns, supplemented with modern patterns popular in the .NET community. Each pattern is examined through the lens of:

• Problem — what task the pattern solves
• Structure — UML class and interaction diagrams
• Implementation — ready-made examples in C# with comments
• Application — where and when the pattern is truly needed, and where it is overkill

Key topics

• Creational patterns: Singleton, Factory Method, Abstract Factory, Builder, Prototype
• Structural patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy
• Behavioral patterns: Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor
• Modern additions: Dependency Injection, Repository, Unit of Work, CQRS, Event Sourcing
• Integration of patterns with ASP.NET Core, Entity Framework Core, WPF, and Blazor

Who this book is for

• Junior developers who want to advance to the Middle level and write maintainable code
• Middle developers looking to systematize their knowledge and learn advanced techniques
• Team Leads and architects seeking examples of pattern application in large projects
• Anyone preparing for technical interviews and wanting to confidently answer questions about patterns

What you will learn

• How to correctly choose a pattern for a specific task, rather than applying patterns "just in case"
• How to combine patterns to build a flexible architecture
• How to avoid anti-patterns and unnecessary code complexity
• How to refactor existing code using patterns
• How to test code built on patterns

The book contains over 50 working examples that can be immediately used in your projects. All examples are accompanied by explanations and links to the source code on GitHub. After reading, you will be able to design systems that are easy to extend, maintain, and test.