using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public class RouteSequence

    {

        public int SeqNum

        {

            get;

            set;

        }

​

        public string SeqName

        {

            get;

            set;

        }

​

        public string SeqLocation

        {

            get;

            set;

        }

    }

​

    public static void Main()

    {

        //RouteSequence r = new RouteSequence(){SeqNum = 1, SeqName = "R01", SeqLocation = "LO1"};

        //view sample data

        Console.WriteLine("Original List");

        var seqlist = new List<RouteSequence>();

        for (var i = 1; i <= 5; i++)

        {

            var rs = new RouteSequence()

            {SeqNum = i, SeqName = "R0" + i, SeqLocation = "LO" + i};

            seqlist.Add(rs);

            Console.WriteLine(string.Format("{0} {1} {2}", rs.SeqNum, rs.SeqName, rs.SeqLocation));

        }

​

        //New row with number - check if exists then reoreder existing from new number on then add new to list

        var newnumber = 1;

        var temp = seqlist.Where(r => r.SeqNum >= newnumber).OrderBy(o => o.SeqNum).ToList();

        temp.ForEach(n =>

        {

            n.SeqNum = (n.SeqNum + 1);

        }

​

        );

        // New Temp List

        Console.WriteLine("\n\nTemp ReOrder List");

        foreach (var rs in temp)

        {

            Console.WriteLine(string.Format("{0} {1} {2}", rs.SeqNum, rs.SeqName, rs.SeqLocation));

        }

​

        //Add New Item to Temp List 

        Console.WriteLine("\n\nAdding New Item to Temp List ");

        temp.Add(new RouteSequence()

        {SeqNum = newnumber, SeqName = "R0-New", SeqLocation = "LO-NEW"});

        Console.WriteLine("\n\nNew List");

        //Print New List with New Item ordered properly

        foreach (var n in temp.OrderBy(o => o.SeqNum))

        {

            Console.WriteLine(string.Format("{0} {1} {2}", n.SeqNum, n.SeqName, n.SeqLocation));

        }

    }

}