Wrapper classes

A wrapper class is any class which "wraps" or "encapsulates" the functionality of  another class or component. These are useful by providing a level of abstraction from the implementation of the underlying class or component;

Not much clear , Right ?

Ok, let me give example from my experience. I have a class for TAX calculation containing method to calculate TAX, and my another class called SALARY calculator is there. Now to calculate salary I want to use TAX calculator class. And my interest is that I will not disclose to other class “How I am calculating TAX”?. Then I will simply wrap my TAX calculator class by SALARY class. 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Collections;

using System.Data.SqlClient;

using System.Data;

using System.Diagnostics;

namespace BlogProject

{

    class Wrapper //Wrapper Class

    {

        class InnerClass //Inner Class

        {

            public Int32 ProcessData(int Val)

            {

                return Val + 1;

            }

        }

        public Int32 CallRapper()

        {

            Wrapper.InnerClass wpr = new Wrapper.InnerClass(); // Internally call to Wrapper class.

            return wpr.ProcessData(100);

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            Wrapper w = new Wrapper();

            Console.WriteLine("Data Process by inner class and show by Wrapper Class:-" + w.CallRapper());

            Console.ReadLine();

        }

    }

}