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Adapter in C#

Adapter is a structural design pattern, which allows incompatible objects to collaborate.

The Adapter acts as a wrapper between two objects. It catches calls for one object and transforms them to format and interface recognizable by the second object.



Usage examples: The Adapter pattern is pretty common in C# code. It’s very often used in systems based on some legacy code. In such cases, Adapters make legacy code work with modern classes.

Identification: Adapter is recognizable by a constructor which takes an instance of a different abstract/interface type. When the adapter receives a call to any of its methods, it translates parameters to the appropriate format and then directs the call to one or several methods of the wrapped object.

Conceptual Example

This example illustrates the structure of the Adapter design pattern. It focuses on answering these questions:

  • What classes does it consist of?
  • What roles do these classes play?
  • In what way the elements of the pattern are related?

Program.cs: Conceptual example

using System;

namespace RefactoringGuru.DesignPatterns.Adapter.Conceptual
    // The Target defines the domain-specific interface used by the client code.
    public interface ITarget
        string GetRequest();

    // The Adaptee contains some useful behavior, but its interface is
    // incompatible with the existing client code. The Adaptee needs some
    // adaptation before the client code can use it.
    class Adaptee
        public string GetSpecificRequest()
            return "Specific request.";

    // The Adapter makes the Adaptee's interface compatible with the Target's
    // interface.
    class Adapter : ITarget
        private readonly Adaptee _adaptee;

        public Adapter(Adaptee adaptee)
            this._adaptee = adaptee;

        public string GetRequest()
            return $"This is '{this._adaptee.GetSpecificRequest()}'";

    class Program
        static void Main(string[] args)
            Adaptee adaptee = new Adaptee();
            ITarget target = new Adapter(adaptee);

            Console.WriteLine("Adaptee interface is incompatible with the client.");
            Console.WriteLine("But with adapter client can call it's method.");


Output.txt: Execution result

Adaptee interface is incompatible with the client.
But with adapter client can call it's method.
This is 'Specific request.'

Adapter in Other Languages

Adapter in C++ Adapter in Go Adapter in Java Adapter in PHP Adapter in Python Adapter in Ruby Adapter in Rust Adapter in Swift Adapter in TypeScript