A structured decision guide for when to use the decorator pattern in C#. Covers key signals that indicate the pattern is appropriate (runtime behavior composition, cross-cutting concerns, subclass explosion, Open/Closed Principle), when to avoid it (simple permanent behavior, performance hot paths, middleware being a better fit), and a four-question decision framework. Includes concrete code examples for payment processing (logging, metrics, authorization decorators) and a composable caching layer for report generation. Also compares decorators against inheritance, middleware, and AOP, and addresses common red flags like overly broad interfaces and deep chains.
Table of contents
Signs You Need the Decorator Pattern in C#When NOT to Use the Decorator PatternDecision Framework for the Decorator Pattern in C#Scenario 1: Adding Logging and Metrics to a Payment ProcessorScenario 2: Composable Caching Layer for ReportsScenario 3: Authorization and Validation Wrapping Service CallsDecorator vs Alternatives: When to Choose WhatRed Flags: When the Decorator Pattern Is OverkillFrequently Asked QuestionsWrapping Up the Decorator Pattern Decision GuideSort: