public class SortableList : BindingList
{
    protected override bool SupportsSortingCore
    {
        get
        {
            return true;
        }
    }

    protected override void ApplySortCore(PropertyDescriptor prop, ListSortDirection direction)
    {
        var sortProperty = prop;
        var sortDirection = direction;

        var list = Items as List;
        list.Sort((T item1, T item2) =>
        {
            var item1Value = item1 == null ? null : sortProperty.GetValue(item1);
            var item2Value = item2 == null ? null : sortProperty.GetValue(item2);
            int result;
            if (item1Value == null)
            {
                result = -1;
            }
            else if (item2Value == null)
            {
                result = 1;
            }
            else
            {
                result = Comparer.Default.Compare(item1Value, item2Value);
            }
            if (sortDirection == ListSortDirection.Descending)
            {
                result = -result;
            }
            return result;
        });
    }
}

This post I wrote long back and it was in draft mode, and today I thought of publishing it

Happy Coding

Stored Procedure – xsp_GetPersons

CREATE PROCEDURE xsp_GetPersons
@StartIndex INT, @Count INT
AS
BEGIN
DECLARE @EndIndex INT
SET @StartIndex = @StartIndex * @Count
SET @EndIndex = @StartIndex + @Count
SELECT * FROM (SELECT ROW_NUMBER() OVER (ORDER BY UserId DESC) AS SlNo, UserId, FirstName, LastName, Email, ISNULL(DOB, GETDATE()) AS DOB FROM U_MyRegistration)Registration WHERE Registration.SlNo BETWEEN @StartIndex AND @EndIndex
END

And I added a DataRepeater control, with Next and Previous buttons in the Footer.

<tr>
    <td colspan="3" align="left">
        <asp:LinkButton CommandName="Navigation" CommandArgument="Prev" runat="server" ID="linkPrevious"
            Text="<< Previous" />
    </td>
    <td colspan="3" align="right">
        <asp:LinkButton CommandName="Navigation" CommandArgument="Next" runat="server" ID="linkNext" Text="Next >>" />
    </td>
</tr>

Code behind. As it is a sample code, I am not added any validations.

int count = 10;
protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        BindData(); //Binding Data.
    }
}

private void BindData()
{
    int startIndex = Convert.ToInt32(this.hidCurrentIndex.Value);
    Persons p = new Persons();
    this.Repeater1.DataSource = null;
    this.Repeater1.DataSource = p.GetPersons(startIndex, count);
    this.Repeater1.DataBind();
}

protected void Repeater1_ItemCommand(object source, RepeaterCommandEventArgs e)
{
    if (e.CommandName.Equals("Navigation",
StringComparison.CurrentCultureIgnoreCase))
    {
        if (e.CommandArgument.ToString().Equals("Prev",
StringComparison.CurrentCultureIgnoreCase))
        {
            this.hidCurrentIndex.Value = (Convert.ToInt32
(this.hidCurrentIndex.Value) - 1).ToString(); //Decrementing the count
            this.BindData();
        }
        else
        {
            this.hidCurrentIndex.Value = (Convert.ToInt32
(this.hidCurrentIndex.Value) + 1).ToString(); //Incrementing the count
            this.BindData();
        }
    }
}

And the implementation of Persons class from App_Code

using System;
using System.Collections.Generic;
using System.Data.SqlClient;

public class Persons : List<Persons.Person>
{
    public class Person
    {
        public int UserId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Email { get; set; }
        public DateTime DOB { get; set; }
    }

    public Persons GetPersons(int startIndex, int count)
    {
        Persons persons = new Persons();
        using (SqlConnection connection = new SqlConnection ("Server=.\SQLEXPRESS;User Id=sa;Password=sapwd;Database=myDatabase"))
        {
            connection.Open();
            using (SqlCommand command = new SqlCommand("xsp_GetPersons",

connection))
            {
                command.CommandType = System.Data.CommandType.StoredProcedure;
                command.Parameters.AddWithValue("@StartIndex", startIndex);
                command.Parameters.AddWithValue("@Count", count);
                SqlDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    persons.Add(new Person()
                    {
                        DOB = Convert.ToDateTime(reader["DOB"].ToString()),
                        Email = reader["Email"].ToString(),
                        FirstName = reader["FirstName"].ToString(),
                        LastName = reader["LastName"].ToString(),
                        UserId = Convert.ToInt32(reader["UserId"].ToString()),
                    });
                }
            }
        }
        return persons;
    }
}

The core thing is stored procedure, which will return the results based on the given index. Thanks to Aneesh for the details of ROW_NUMBER() function.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
  If Not Page.IsPostBack Then
  Dim students As New Hashtable
  students.Add("1", "Student1")
  students.Add("2", "Student2")
  students.Add("3", "Student3")
  students.Add("4", "Student4")
  students.Add("5", "Student5")
  StudentDropdown.DataTextField = "Value"
  StudentDropdown.DataValueField = "key"
  StudentDropdown.DataSource = students
  StudentDropdown.DataBind()
  End If
End Sub

And set the Autopostback property of the StudentDropdown to True. And in the SelectedIndexChanged event, write the code to set the value of the Dropdown to the Textbox.

Protected Sub StudentDropdown_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles StudentDropdown.SelectedIndexChanged
        If uxSample.SelectedIndex  <> -1 Then
            StudentId.Text = StudentDropdown.Items(StudentDropdown.SelectedIndex).Value
        End If
End Sub