How to implement Strategy Design Pattern in C#

Strategy Design Pattern

In software engineering, a software design pattern is a general, reusable solution to a commonly occurring problem within a given context in software design. It is not a finished design that can be transformed directly into source or machine code

In this blog post I will discuss about one of the most used design pattern "Strategy design pattern"

By the end of this blog post you will be able to understand

• What is Strategy design pattern?
• How to implement Strategy design pattern in C# with real world example
• Where to use Strategy design pattern? 

What is Strategy design pattern?

Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it.

Problem

Client wants to decide at run-time what serialization it should use to serialize a type. Many different serialization algorithms are already available.

Solution

Encapsulate the different serialization algorithms using the Strategy pattern!

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace StrategyPattern
{

    public interface ISerializer
    {
        void Serialize();
    }
    public class XmlSerializer : ISerializer
    {
        public void Serialize()
        {
            Console.WriteLine("Xml serilizer Invoked");
        }
    }
    public class JsonSerializer : ISerializer
    {
        public void Serialize()
        {
            Console.WriteLine("Json serializer Invoked");
        }
    }
    public class Context
    {
        private ISerializer _serializer;
        public Context(ISerializer serializer)
        {
            this._serializer = serializer;
        }
        public void Serialize()
        {
            _serializer.Serialize();
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Context ctx = new Context(new XmlSerializer());
            ctx.Serialize();
        }
    }
}

Patterns You’re Already Using in the .NET Framework.

.NET Framework List<T> and ArrayList Sort method uses Strategy design pattern in the Sort method.

Sort<T>(T[], IComparer<T>)

Refrences

• Do Factory