Sorting in grid view using Generic List

In this example we create a class student and bind grid view using generic list of student type and add storing on generic list to bind grid view.

Sorting in grid view using Generic List

In this example we create a class student and bind grid view using generic list of student type and add storing on generic list to bind grid view.

Student.cs

using System.Collections.Generic;
/// <summary>
/// Summary description for Student
/// </summary>
public class Student
{
    public Student()
    {
        //
        // TODO: Add constructor logic here
        //
    }
    public string RollNo { get; set; }
    public string StudentName { get; set; }
    public List<Student> GetStudentList()
    {
        List<Student> lstStudent = new List<Student>();
        Student objStudent1 = new Student();
        objStudent1.RollNo = "23";
        objStudent1.StudentName = "Ravi Shrivastav";
        lstStudent.Add(objStudent1);
        Student objStudent2 = new Student();
        objStudent2.RollNo = "46";
        objStudent2.StudentName = "Nitin Kumar";
        lstStudent.Add(objStudent2);
        Student objStudent3 = new Student();
        objStudent3.RollNo = "37";
        objStudent3.StudentName = "Neha Gupta";
        lstStudent.Add(objStudent3);
        Student objStudent4 = new Student();
        objStudent4.RollNo = "36";
        objStudent4.StudentName = "Markandey Pathak";
        lstStudent.Add(objStudent4);
        Student objStudent5 = new Student();
        objStudent5.RollNo = "56";
        objStudent5.StudentName = "Rahul Porwal";
        lstStudent.Add(objStudent5);
        Student objStudent6 = new Student();
        objStudent6.RollNo = "40";
        objStudent6.StudentName = "Piyush Pandey";
        lstStudent.Add(objStudent6);
        return lstStudent;
    }
}

Default.aspx

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
    <h2>Sorting in GridView using list</h2>
    <div style="font-size: 14px; color: #000;">
        <asp:GridView ID="gdvStudent" runat="server"
            AllowSorting="true"
            AutoGenerateColumns="false" OnSorting="gdvStudent_Sorting" Width="300px">
            <Columns>
                <asp:BoundField DataField="RollNo" HeaderText="Roll No" SortExpression="RollNo" />
                <asp:BoundField DataField="StudentName" HeaderText="Student Name" SortExpression="StudentName" />
            </Columns>
        </asp:GridView>
    </div>
</asp:Content>

Default.aspx.cs 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.UI.WebControls;
using System.Reflection;
public partial class _Default : System.Web.UI.Page
{
    List<Student> lstStudent = null;
    Student objStudent = new Student();
    protected void Page_Load(object sender, EventArgs e)
    {
        lstStudent = objStudent.GetStudentList();
        if (!IsPostBack)
        {
            gdvStudent.DataSource = lstStudent;
            gdvStudent.DataBind();
        }
    }
    /// <summary>
    /// Gridview sorting event
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void gdvStudent_Sorting(object sender, GridViewSortEventArgs e)
    {
        string Sortdir = GetSortDirection(e.SortExpression);
        string SortExp = e.SortExpression;
        var list = objStudent.GetStudentList();
        if (Sortdir == "ASC")
        {
            list = Sort<Student>(list, SortExp, SortDirection.Ascending);
        }
        else
        {
            list = Sort<Student>(list, SortExp, SortDirection.Descending);
        }
        this.gdvStudent.DataSource = list;
        this.gdvStudent.DataBind();
    }
    /// <summary>
    /// GEt Sorting direction
    /// </summary>
    /// <param name="column"></param>
    /// <returns></returns>
    private string GetSortDirection(string column)
    {
        string sortDirection = "ASC";
        string sortExpression = ViewState["SortExpression"] as string;
        if (sortExpression != null)
        {
            if (sortExpression == column)
            {
                string lastDirection = ViewState["SortDirection"] as string;
                if ((lastDirection != null) && (lastDirection == "ASC"))
                {
                    sortDirection = "DESC";
                }
            }
        }
        ViewState["SortDirection"] = sortDirection;
        ViewState["SortExpression"] = column;
        return sortDirection;
    }
    /// <summary>
    /// Sort function
    /// </summary>
    /// <typeparam name="TKey"></typeparam>
    /// <param name="list"></param>
    /// <param name="sortBy"></param>
    /// <param name="direction"></param>
    /// <returns></returns>
    public List<Student> Sort<TKey>(List<Student> list, string sortBy, SortDirection direction)
    {
        PropertyInfo property = list.GetType().GetGenericArguments()[0].GetProperty(sortBy);
        if (direction == SortDirection.Ascending)
        {
            return list.OrderBy(e => property.GetValue(e, null)).ToList<Student>();
        }
        else
        {
            return list.OrderByDescending(e => property.GetValue(e, null)).ToList<Student>();
        }
    }
}