Build a backend management system for ASP. Mvc4+ef5+easyui+unity2.x Injection (16)-Privilege management system-Beautiful verification code

We built a database table in the last section, but I found a lot of things have not been perfected, such as verification code, we first do a verification code bar, verification code we are familiar with, in order to prevent malicious login, we must add a verification code on the login page, below I will share a verification code, this is a C # painting, the principle is, Generate a random 4-digit number, save it as a session or a cookie, and compare the verification code entered by the user,

The captcha can be a view cshtml, an ASPX page, or a ashx generic handler, which we use ASHX to display

In the core folder under App.admin, create a new generic processing file verify_code.ashx, copy the following code (this CAPTCHA applies to the ASPX program)

usingSystem;usingSystem.IO;usingSystem.Drawing;usingSystem.Drawing.Imaging;usingsystem.web;usingSystem.Web.SessionState;namespaceapp.admin{/// <summary>    ///Verification code Generation class/// </summary>     Public classVerify_code:ihttphandler, IRequiresSessionState { Public voidProcessRequest (HttpContext context) {intCodew = the; intCodeh = A; intFontSize = -; stringChkcode =string.            Empty; //List of colors for verification codes, noise lines, noise pointscolor[] color ={color.black, color.red, Color.Blue, Color.green, Color.orange, Color.brown, Color.brown, Color.DarkBlue}; //font list, for verification code            string[] Font = {"Times New Roman","Verdana","Arial","Gungsuh","Impact" }; //The character set of the captcha, removing some easily confusing characters            Char[] character = {'2','3','4','5','6','8','9','a','b','D','e','F','h','k','m','N','R','x','y','A','B','C','D','E','F','G','H','J','K','L','M','N','P','R','S','T','W','X','Y' }; Random Rnd=NewRandom (); //Generate Authenticode String             for(inti =0; I <4; i++) {Chkcode+=Character[rnd. Next (character.            Length)]; }            //Write SessionContext. session["Code"] =Chkcode; //Create a canvasBitmap BMP =NewBitmap (Codew, Codeh); Graphics g=graphics.fromimage (BMP);            G.clear (Color.White); //Draw Noise Line             for(inti =0; I <1; i++)            {                intX1 =Rnd.                Next (Codew); intY1 =Rnd.                Next (Codeh); intx2 =Rnd.                Next (Codew); inty2 =Rnd.                Next (Codeh); Color CLR=Color[rnd. Next (color.                Length)]; G.drawline (NewPen (CLR), x1, y1, x2, y2); }            //draw a Captcha string             for(inti =0; i < chkcode.length; i++)            {                stringFNT =Font[rnd. Next (font.                Length)]; Font ft=NewFont (FNT, fontSize); Color CLR=Color[rnd. Next (color.                Length)]; g.DrawString (Chkcode[i]. ToString (), FT,NewSolidBrush (CLR), (floatI -+2, (float)0); }            //Draw Noise points             for(inti =0; I < -; i++)            {                intx =Rnd. Next (BMP.                Width); inty =Rnd. Next (BMP.                Height); Color CLR=Color[rnd. Next (color.                Length)]; Bmp.            SetPixel (x, Y, CLR); }            //clear the page output cache, set the page without cachingContext. 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"); //writes a captcha picture to the memory stream and outputs it in "image/png" formatMemoryStream ms =NewMemoryStream (); Try{BMP.                Save (MS, Imageformat.png); Context.                Response.clearcontent (); Context. Response.ContentType="Image/png"; Context. Response.BinaryWrite (Ms.            ToArray ()); }            finally            {                //explicitly releasing resourcesbmp.                Dispose ();            G.dispose (); }        }         Public BOOLisreusable {Get            {                return false; }        }    }}

View Code

Write session
Context. session["Code" = Chkcode;
Call this page will generate a session, we will compare with the user input code, OK back to the account's index view

Embed this page in the location of the verification code

<tr>                            <td style= "width:80px; Text-align:right" > Verification Code:                            </td>                            <td>                                 <input Style= "width:50px" type= "text" name= "Validatecode" id= "Validatecode"/>                                                                <a href=" javascript:$ (' #codeImg '). Trigger (' click ') ' > not clear? </a>                            </td>                        </tr>

Preview after compiling

Build a backend management system for ASP. Mvc4+ef5+easyui+unity2.x Injection (16)-Privilege management system-Beautiful verification code