Ajax+asp.net to achieve User login _ practical skills

Take user Login As an example to practice the use of Ajax

Login.html

<! DOCTYPE html>  

DAL.cs

Using System;
Using System.Collections.Generic;
Using System.Data;
Using System.Data.SqlClient;
Using System.Linq;
Using System.Web;
 
Namespace Ajaxtest
{public
  class DAL
  {
    private string connstr = ' Server=acer-pc;database=mydatabase ; user id=sa;password=123456 ";
    Public DataTable Selectdb (String sql)
    {
      datatable dt = new DataTable ();
      Try
      {
        SqlConnection conn = new SqlConnection (CONNSTR);
        SqlDataAdapter SDA = new SqlDataAdapter (SQL, conn);
        Sda. Fill (DT);
      }
      catch (Exception e)
      {} return
      dt;
    }
  }
}

BLL.cs

Using System;
Using System.Collections.Generic;
Using System.Data;
Using System.Linq;
Using System.Web;
 
Namespace Ajaxtest
{public
  class BLL
  {public
    bool Login (string username,string password)
    {
      Try
      {
        String sql = "Select password from Users where username= '" + username + "'";
        Dal sqlselect = new Dal ();
        DataTable dt = SQLSELECT.SELECTDB (sql);
        if (dt. rows[0]["Password"]. ToString ()!= password) return
          false;
      }
      catch (Exception)
      { 
      } return
      true;
    }
}}

Server.aspx.cs

Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Web;
Using System.Web.UI;
Using System.Web.UI.WebControls;
 
Namespace Ajaxtest
{public
  partial class Server:System.Web.UI.Page
  {
    protected void Page_Load ( Object sender, EventArgs e)
    {
      string username = request[' username ']. ToString ();
      string password = request["Password"]. ToString ();
      BLL B = new BLL ();
      if (B.login (username, password))
      {
        Response.Write ("Login succeeded");
        Response.End ();
      }
      else
      {
        Response.Write ("Login Failed");
        Response.End ();}}}

Server.aspx

<%@ Page language= "C #" autoeventwireup= "true" codebehind= "Server.aspx.cs" inherits= "Ajaxtest.server"%>
 
<! DOCTYPE html>
 
 
 

The above mentioned is the entire content of this article, I hope you can enjoy.