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Adapter

Adapter in C#

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

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.

Learn more about Adapter

Usage of the pattern in C#

Complexity:

Popularity:

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 with modern classes.

Identification: Adapter is recognizable by a constructor which takes an instance of different abstract/interface type. When adapter receives a call to any of its methods, it translates parameters to 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 consists 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.");

            Console.WriteLine(target.GetRequest());
        }
    }
}

Output.txt: Output

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 Java Adapter in PHP Adapter in Python Adapter in TypeScript