Design Patterns in C#

A comprehensive guide to design patterns in C#, inspired by the Gang of Four (GoF) book. This repository contains documentation and minimalistic code samples demonstrating each design pattern.

Repository Structure

The patterns are organized into three main categories:

Creational Patterns

Patterns that deal with object creation mechanisms.

• Singleton - Ensures a class has only one instance
• Factory Method - Creates objects without specifying exact classes
• Abstract Factory - Creates families of related objects
• Builder - Constructs complex objects step by step
• Prototype - Creates new objects by copying existing ones

Structural Patterns

Patterns that deal with object composition and relationships.

• Adapter - Allows incompatible interfaces to work together
• Bridge - Separates abstraction from implementation
• Composite - Composes objects into tree structures
• Decorator - Adds behavior to objects dynamically
• Facade - Provides a simplified interface to a complex system
• Flyweight - Shares common state between multiple objects
• Proxy - Provides a surrogate or placeholder for another object

Behavioral Patterns

Patterns that deal with object collaboration and responsibility.

• Chain of Responsibility - Passes requests along a chain of handlers
• Command - Encapsulates a request as an object
• Iterator - Accesses elements of a collection sequentially
• Mediator - Defines how objects interact
• Memento - Captures and restores an object's state
• Observer - Notifies multiple objects about state changes
• State - Alters object behavior when its state changes
• Strategy - Defines a family of interchangeable algorithms
• Template Method - Defines the skeleton of an algorithm
• Visitor - Separates algorithms from objects they operate on

How to Use

Each pattern directory contains:

• README.md - Documentation explaining the pattern
• A minimalistic C# application demonstrating the pattern

Requirements

These samples are built with:

• .NET 10 - The latest LTS release with enhanced runtime performance
• C# 14 - Featuring new language improvements including:
  • field keyword for cleaner property implementations
  • Null-conditional assignment (?.=)
  • Extension members and improved Span<T> support
  • Enhanced lambda expressions

To run the samples, install the .NET 10 SDK.

Contributing

Feel free to contribute by adding more examples or improving existing documentation.