How to Validate User Login in asp.net using DataSet?

Is it working and you didnt understand the concept? or its not working?

If you didnt understand the code, then check my previous answer,..I have added comments now to explain the code

Here am loading all the users into datatable and checking whetehr the user exists.

//Get all records from user table and fill it to adapter
SqlDataAdapter adapter = new SqlDataAdapter("select * from Users", connection);
  DataTable dt = new DataTable();
//Fill the adapter to datatable
  adapter.Fill(dt);
//This will be the linq query in which first am converting datatable as Enumerable. If its Enumerable, then we can loop and query each records . Then am using Linq and checking whether Username column inside datatable(now its enumerable) has value User1 and also samething for password. if it matches, then i am selecting the columns i wanted such as userid, password, name,etc
  var user=from u in dt.AsEnumerable()
  where u.Field("UserName")=="user1"
  && u.Field("Password")=="pwd"
  select new {
  userId=u.Field("UserId"),
  userName=u.Field("UserName"),
  Password=u.Field("Password")
  };

Hi Rani,


<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="login_using_parameter._Default" %>





   


   

   

   

                 Width="100px" BackColor="#FFFF66" ForeColor="#FF3300">
       

                    Width="100px" BackColor="#FFFF66" ForeColor="#FF3300">
                    TextMode="Password" Width="100px">

                    BackColor="#CCFF99" onclick="btn_login_Click"  />

   

  
   

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
namespace login_using_parameter
{
    public partial class _Default : System.Web.UI.Page
    {
        string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        string str = null;
        SqlCommand com;
      
        protected void btn_login_Click(object sender, EventArgs e)
        {
            object obj = null;
            SqlConnection con = new SqlConnection(strConnString);
            con.Open();
            str = "select count(*) from login where UserName=@UserName and Password =@Password";
            com = new SqlCommand(str, con);
            com.CommandType = CommandType.Text;
            com.Parameters.AddWithValue("@UserName", TextBox_user_name.Text);
            com.Parameters.AddWithValue("@Password", TextBox_password.Text);
            obj = com.ExecuteScalar();
            if ((int)(obj) != 0)
            {
                lb1.Text = "WELLCOME :: " + TextBox_user_name.Text;
            }
            else
            {
                lb1.Text = "invalid user name and password";
            }
            con.Close();
        }
    }
}



Thanks