ASP. Net authentication code login

One . explain

This article is Xiaobai learning Morni Chang Teacher's video teaching <<Asp.Net WEB Server programming technology >> Study notes made in , Some knowledge points follow the tutorial , You can also go to the teacher's homepage to learn , Thank you. .

Two . Generate captcha image (CodeHandler.ashx)

Previous section , We use checkcode.aspx.cs To process the generated verification code image , Today we are Handler Folder to create a general handler CodeHandler.ashx, Instead of . The code is as follows :

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.SessionState;

namespace MyMusci.Handler
{
    
    /// <summary>
    /// CodeHandler  Summary description of 
    /// </summary>
    public class CodeHandler : IHttpHandler, IRequiresSessionState
    {
    

        public void ProcessRequest(HttpContext context)
        {
    
            context.Response.ContentType = "text/plain";
            string chkCode = string.Empty;
            int ix, iy;
            ix = 140;
            iy = 40;
            // Color list , Used for verification code 、 Noise line 、 noise  
            Color[] color = {
     Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            // Font list , Used for verification code  
            string[] font = {
     "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "MingLiU", "Arial" };
            // The character set of the captcha , Removed some confusing characters  
            char[] character = {
     '2', '3', '4', '5', '6', '8', '9', '0', '1', ' Small ', ' white ' };
            Random rnd = new Random();
            // Generate captcha string  
            for (int i = 0; i < 4; i++)
            {
    
                chkCode += character[rnd.Next(character.Length)];
            }
            Bitmap bmp = new Bitmap(ix, iy);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            // Draw a noise line  
            for (int i = 0; i < 10; i++)
            {
    
                int x1 = rnd.Next(ix);
                int y1 = rnd.Next(iy);
                int x2 = rnd.Next(ix);
                int y2 = rnd.Next(iy);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            }
            // Draw the verification code string  
            for (int i = 0; i < chkCode.Length; i++)
            {
    
                string fnt = font[rnd.Next(font.Length)];
                Font ft = new Font(fnt, iy/2, FontStyle.Bold);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 30 + 2, (float)2);
            }
            // Painting noise  
            for (int i = 0; i < 50; i++)
            {
    
                int x = rnd.Next(bmp.Width);
                int y = rnd.Next(bmp.Height);
                Color clr = color[rnd.Next(color.Length)];
                bmp.SetPixel(x, y, clr);
            }
            // Write the verification code to SESSION, Why can't the second page get the value ？？？
            // General handler adds interface file ;
            HttpContext.Current.Session["Code"] = chkCode.ToUpper();
            // Clear the page output cache , Set this page to have no cache  
            context.Response.Buffer = true;
            context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
            context.Response.Expires = 0;
            context.Response.CacheControl = "no-cache";
            context.Response.AppendHeader("Pragma", "No-Cache");
            // Write the verification code image to the memory stream , And put it in  "image/Png"  Format output  
            // My page returns pictures ;
            MemoryStream ms = new MemoryStream();
            try
            {
    
                bmp.Save(ms, ImageFormat.Png);
                context.Response.ClearContent();
                context.Response.ContentType = "image/Png";
                context.Response.BinaryWrite(ms.ToArray());
            }
            finally
            {
    
                // Explicitly release resources  
                bmp.Dispose();
                g.Dispose();
            }
        }

        public bool IsReusable
        {
    
            get
            {
    
                return false;
            }
        }
    }
}

3、 ... and . Add verification code to the login page (login_new.aspx)

Because we changed the verification code generator , Therefore, you should also change the corresponding code in the login interface :

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="login_new.aspx.cs" Inherits="MyMusci.login_new" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
    <link href="bootstrap-5.1.3-dist/css/bootstrap.css" rel="stylesheet" />
   <script src="bootstrap-5.1.3-dist/js/bootstrap.bundle.js"></script>
    <script src="js/jquery.js"></script>
    <style> /* Log in the entire div Vertical center */ .all {
       width: 700px; height: 260px; background-color: rgba(205,197,191,0.8); position: absolute; top: 0; bottom: 0; left: 0; right: 0; margin: auto; padding:0; } body {
       background-image: url("img/dm.jpg"); /* The whole picture as the background , Not enough auto stretch */ background-size: cover; } </style>
</head>
<body>
    <form id="form1" runat="server">
        <div class="container mt-3">
            <asp:ScriptManager ID="ScriptManager1" runat="server">
            </asp:ScriptManager>
            <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                <ContentTemplate>
                    <table class="table all">
                        <tr>
                            <td class="table-primary display-3 text-center text-primary" colspan="3"> Login screen </td>
                        </tr>
                        <tr>
                            <td> Account </td>
                            <td>
                                <asp:TextBox ID="userName" runat="server"></asp:TextBox>
                            </td>
                            <td>
                                <asp:RequiredFieldValidator ID="rfv_useName" runat="server" ControlToValidate="userName" Display="Dynamic" ErrorMessage="RequiredFieldValidator" ForeColor="Red"> Account cannot be empty </asp:RequiredFieldValidator>
                                <asp:RegularExpressionValidator ID="rev_userName" runat="server" ControlToValidate="userName" Display="Dynamic" ErrorMessage="RegularExpressionValidator" ForeColor="Red" ValidationExpression="\w{5,13}"> The account you entered is abnormal (5-12 position )</asp:RegularExpressionValidator>
                            </td>
                        </tr>
                        <tr>
                            <td class="auto-style2"> password </td>
                            <td class="auto-style2">
                                <asp:TextBox ID="userPwd" runat="server"></asp:TextBox>
                            </td>
                            <td class="auto-style2">
                                <asp:RequiredFieldValidator ID="rfv_userPwd" runat="server" ControlToValidate="userPwd" Display="Dynamic" ErrorMessage="RequiredFieldValidator" ForeColor="Red"> The password cannot be empty </asp:RequiredFieldValidator>
                                <asp:RegularExpressionValidator ID="rev_userPwd" runat="server" ControlToValidate="userPwd" Display="Dynamic" ErrorMessage="RegularExpressionValidator" ForeColor="Red" ValidationExpression="\w{8,13}"> The password you entered is abnormal (8 position )</asp:RegularExpressionValidator>
                            </td>
                        </tr>
                        <tr>
                            <td>
                                 Verification Code </td>
                            <td>
                                <asp:TextBox ID="code" runat="server"></asp:TextBox>
                            </td>
                            <td><img id="imgcode" src="Handler/CodeHandler.ashx" />
                                <asp:Label ID="codeText" runat="server" Text=""></asp:Label></td>
                        </tr>
                        <tr>
                            <td>
                                <asp:Button ID="btn_sub" runat="server" class="btn btn-primary" OnClick="btn_sub_Click" Text=" Sign in " />
                            </td>
                            <td>
                                <asp:LinkButton ID="LinkButton1" runat="server" class="btn btn-secondary" PostBackUrl="~/RegUser.aspx" CausesValidation="False"> register </asp:LinkButton>
                            </td>
                            <td>&nbsp;</td>
                        </tr>
                    </table>
                </ContentTemplate>
            </asp:UpdatePanel>
        </div>
    </form>
    
    <script> // Picture click event  $("#imgcode").click(function () {
       $("#imgcode").attr("src", "Handler/CodeHandler.ashx?t=" + Math.random()); }) </script>
</body>
</html>

The background code is also added as the corresponding code (login_new.aspx.cs):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Collections;

namespace MyMusci
{
    
    public partial class login_new : System.Web.UI.Page
    {
    
        protected void Page_Load(object sender, EventArgs e)
        {
    

        }

        /// <summary>
        ///  Reset button click event 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btn_reset_Click(object sender, EventArgs e)
        {
    
            userName.Text = "";
            userPwd.Text = "";
        }
        /// <summary>
        ///  Login button click event 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btn_sub_Click(object sender, EventArgs e)
        {
    
            // test 
            //if ("administrator".Equals(userName.Text) && "12345678".Equals(userPwd.Text)) {
    
            // Response.Redirect("index.aspx");
            //}
			
			// Here, it is determined whether the validation control passes , If not , Then return to 
            if (!rev_userName.IsValid || !rev_userPwd.IsValid) {
    
                return;
            }
            // Here, it is judged whether the user has entered the value of the input box of the verification code , If there is no input , Prompt the user , And back to 
            if (code.Text != Session["Code"].ToString())
            {
    
                codeText.Text = " The verification code is incorrect , Please re-enter ";
                return;
            }
            // Otherwise, clear the prompt value , And let the code run normally 
            else {
    
                codeText.Text = "";
            }

            string sql = "SELECT COUNT(*) FROM user_all WHERE user_name=?name AND user_pwd=?pwd";
            Hashtable ht = new Hashtable();
            ht.Add("name", userName.Text.ToString());
            ht.Add("pwd", ChangPwd.UserMd5(userPwd.Text.ToString()));
            int resilc = ToolMysqlDate.excutScal(sql, ht);

            if (resilc > 0)
            {
    
                // Bind the user name to Session
                Session["userName"] = userName.Text.ToString();

                //Response Is the response from the server , Consume resources , Server memory and network bandwidth 
                //Response.Redirect("index.aspx");
                ScriptManager.RegisterStartupScript(UpdatePanel1, typeof(UpdatePanel), "ok_login", "alert(' You have successfully signed in !');location.href='index.aspx'", true);
            }
            else
            {
    
                //Response.Write("<script>alert(' The account or password you entered is incorrect , Please check and enter !!!')</script>");
                ScriptManager.RegisterStartupScript(UpdatePanel1, typeof(UpdatePanel), "error_login", "alert(' The account or password you entered is incorrect , Please check and enter !!!')", true);
            }
        }

    }
}

Four . effect

When the verification passes , And the verification code is correct :

When the verification code is incorrect :