How to move datarow up and down in gridview in C# asp.net

Source code:-      

<asp:GridView ID="GridView1" Font-Names="Times New Roman" Font-Size="9pt" runat="server"

        AutoGenerateColumns="False" CellPadding="3" GridLines="None"

        BorderColor="White" BorderStyle="Ridge" BackColor="White"

        BorderWidth="2px" CellSpacing="1">

        <PagerStyle BackColor="#C6C3C6" ForeColor="Black" HorizontalAlign="Right" />

        <RowStyle BackColor="#DEDFDE" ForeColor="Black" />

        <Columns>

            <asp:TemplateField HeaderText="Name">

                <ItemTemplate>

                    <asp:TextBox ID="txtname" runat="server" Text='<%# Eval("Name") %>'>  </asp:TextBox>

                </ItemTemplate>

            </asp:TemplateField>

            <asp:TemplateField HeaderText="Phone number">

                <ItemTemplate>

                    <asp:TextBox ID="txtphone" runat="server" Text='<%# Eval("Phone") %>'>   </asp:TextBox>

                </ItemTemplate>

            </asp:TemplateField>

            <asp:TemplateField>

                <ItemTemplate>

                    <asp:Button ID="btnUp" Width="30px" ForeColor="White" Height="20px" Font-Bold="true"

                        OnClick="MoveGridViewRows" ToolTip="Move Up" Font-Size="Medium" BorderStyle="None"

                        BackColor="#507CD1" CommandName="Up" runat="server" Text="&uArr;" />

                </ItemTemplate>

            </asp:TemplateField>

            <asp:TemplateField>

                <ItemTemplate>

                    <asp:Button ID="btnDown" Width="30px" ForeColor="White" Height="20px" Font-Bold="true"

                        OnClick="MoveGridViewRows" ToolTip="Move Down" Font-Size="Medium" BorderStyle="None"

                        BackColor="#507CD1" CommandName="Down" runat="server" Text="&dArr;" />

                </ItemTemplate>

            </asp:TemplateField>

        </Columns>

        <FooterStyle BackColor="#C6C3C6" ForeColor="Black" />

        <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#E7E7FF" />

        <SelectedRowStyle BackColor="#9471DE" Font-Bold="True" ForeColor="White" />

        <SortedAscendingCellStyle BackColor="#F1F1F1" />

        <SortedAscendingHeaderStyle BackColor="#594B9C" />

        <SortedDescendingCellStyle BackColor="#CAC9C9" />

        <SortedDescendingHeaderStyle BackColor="#33276A" />

    </asp:GridView>

Design:-

C# code:-

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {          //Test Records       

            GridView1.DataSource = Enumerable.Range(1, 5).Select(a => new

            {

                Name = String.Format("Name {0}", a),

                Phone = String.Format("Phone {0}", a),

            });

            GridView1.DataBind();

        }

    }

    protected void MoveGridViewRows(object sender, EventArgs e)

    {

        Button btnUp = (Button)sender;

        GridViewRow row = (GridViewRow)btnUp.NamingContainer;

        // Get all items except the one selected   

        var rows = GridView1.Rows.Cast<GridViewRow>().Where(a => a != row).ToList();

        switch (btnUp.CommandName)

        {

            case "Up":

                //If First Item, insert at end (rotating positions)       

                if (row.RowIndex.Equals(0))

                    rows.Add(row);

                else

                    rows.Insert(row.RowIndex - 1, row);

                break;

            case "Down":

                //If Last Item, insert at beginning (rotating positions)    

                if (row.RowIndex.Equals(GridView1.Rows.Count - 1))

                    rows.Insert(0, row);

                else

                    rows.Insert(row.RowIndex + 1, row);

                break;

        } GridView1.DataSource = rows.Select(a => new

   {

       Name = ((TextBox)a.FindControl("txtname")).Text,

       Phone = ((TextBox)a.FindControl("txtphone")).Text,

   }).ToList();

        GridView1.DataBind();

    }

}