using System;

using System.Collections;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        List<Columns> lstCol = new List<Columns>();

        lstCol.Add(new Columns { Name="ID" });

        lstCol.Add(new Columns { Name="Name" });

        lstCol.Add(new Columns { Name="Place" });

        lstCol.Add(new Columns { Name="Work" });

​

        Console.WriteLine("Before:");

        new Print().WriteList(lstCol);

        new CollectionHelper().Swap(lstCol, 2, 3);

        Console.WriteLine("After:");

        new Print().WriteList(lstCol);

    }

}

public class Print

{

    public void WriteList(List<Columns> ListObjects)

    {

        foreach(Columns col in ListObjects)

        {

            Console.WriteLine(col.Name);

        }

        Console.WriteLine();

    }

}

​

public class Columns

{

    public string Name{get;set;}

}

​

​

public class CollectionHelper

{

    public void Swap<T>(List<T> ListObjects, int start, int end)

    {

        T itemData =  ListObjects[start];

        ListObjects[start] = ListObjects[end];

        ListObjects[end] = itemData;

    }

}