ASP. NET MVC implements website verification code function

Website to add a verification code, mainly to prevent the robot program bulk registration, or specific users of the registration of a specific program of violence to crack the way to continue to login, irrigation and other harmful site operations. Verification code is widely used in registration, login, messages and other information submitted to the server-side processing of the page.

It is easy to apply the CAPTCHA in ASP, there are a lot of solutions on the web. Recently in an OA project, because of the ASP. NET MVC framework used in the system, the verification code is also required on the login page, so the verification code originally used in the ASP is migrated to ASP.

　　The class file that the original ASP. NET site uses to generate the Captcha ValidateCode.cs:

Using system;using system.drawing;using system.drawing.imaging;using system.web.ui;using System.Drawing.Drawing2D; Using System.io;namespace senioa.mvc{///<summary>////</summary> public class Valida for code generation Tecode {public Validatecode () {}///<summary>//Maximum length of verification code///</        summary> public int MaxLength {get {return 10;}            }///<summary>///Minimum length of verification code///</summary> public int MinLength {        get {return 1;} }///<summary>//Generate verification codes///</summary>//<param name= "Length" > Specify the lengths of the Captcha &L            t;/param>//<returns></returns> public string createvalidatecode (int length) {            int[] randmembers = new Int[length];            int[] validatenums = new Int[length];            String validatenumberstr = "";        Generate a starting Sequence value    int seekseek = unchecked ((int) DateTime.Now.Ticks);            Random Seekrand = new Random (Seekseek);            int beginseek = (int) seekrand.next (0, Int32.maxvalue-length * 10000);            Int[] seeks = new Int[length];                for (int i = 0; i < length; i++) {Beginseek + = 10000;            Seeks[i] = Beginseek; }//Generate random numbers for (int i = 0; i < length; i++) {Random rand = new Random (                Seeks[i]);                int pownum = 1 * (int) Math.pow (ten, length); Randmembers[i] = rand.            Next (Pownum, Int32.MaxValue); }//extract random numbers for (int i = 0; i < length; i++) {String numstr = Randmembe Rs[i].                ToString ();                int numlength = Numstr.length;                Random rand = new Random (); int numposition = rand.                Next (0, numLength-1); Validatenums[i] = int32.parse (numstr.substring (numPosition, 1)); }//Generate Verification code for (int i = 0; i < length; i++) {validatenumberstr + = valid Atenums[i].            ToString ();        } return VALIDATENUMBERSTR; }///<summary>//Create a picture of the captcha///</summary>//<param name= "Containspage" > To Output to Page object </param>//<param name= "Validatenum" > Captcha </param> public void Createvalidategra Phic (String validatecode) {Bitmap image = new Bitmap ((int) math.ceiling (validatecode.length * 12.0), 22)            ;            Graphics g = graphics.fromimage (image);                try {//Generate random generator randomly random = new random ();                Empty the picture background color g.clear (color.white); The interference line for the picture is (int i = 0; i <; i++) {int x1 = random. Next (image.                    Width); int x2 = random. Next (image. Width); int y1 = random. Next (image.                    Height); int y2 = random. Next (image.                    Height);                G.drawline (New Pen (color.silver), x1, y1, x2, y2); } font font = new Font ("Arial", FontStyle.Bold |                Fontstyle.italic)); LinearGradientBrush brush = new LinearGradientBrush (new Rectangle (0, 0, image. Width, image.                Height), Color.Blue, color.darkred, 1.2f, true);                g.DrawString (Validatecode, Font, Brush, 3, 2); The foreground of the painting picture interferes with the point for (int i = 0; i <; i++) {int x = random. Next (image.                    Width); int y = random. Next (image.                    Height); Image. SetPixel (x, Y, Color.FromArgb (random.                Next ())); }//Draw the border line of the picture G.drawrectangle (new Pen (Color.silver), 0, 0, image. Width-1, image.                HEIGHT-1); Save picture Data MemoryStream stream = new MemorYstream (); Image.                Save (stream, imageformat.jpeg);                Output picture stream containsPage.Response.Clear ();                ContainsPage.Response.ContentType = "Image/jpeg"; ContainsPage.Response.BinaryWrite (stream.            ToArray ());                } finally {g.dispose (); Image.            Dispose (); }}///<summary> Get the length of the CAPTCHA picture///</summary>//<param name= "Validat Enumlength "> Length of verification code </param>//<returns></returns> public static int getimagewidth (int        Validatenumlength) {return (int) (VALIDATENUMLENGTH * 12.0);        }//<summary>//The height of the verification code///</summary>//<returns></returns>        public static double Getimageheight () {return 22.5; }    }}

To fit the ASP. NET. MVC framework, the method of modifying its output picture stream is createvalidategraphic:

View Code

In Controller.cs, add an action to set the generated verification code to the session and output the CAPTCHA image:

Public ActionResult Getvalidatecode () {    Validatecode vcode = new Validatecode ();    String code = Vcode.createvalidatecode (5);    session["Validatecode"] = code;    byte[] bytes = vcode.createvalidategraphic (code);    Return File (bytes, @ "Image/jpeg");}

To be called: in the page that needs to use the verification code, add the tag:

To account/login this action, simply add the validation code to the session:

[Acceptverbs (Httpverbs.post)]public actionresult Login (string userName, string password, bool RememberMe, string Returnurl,string code) {    if (session["Validatecode"). ToString ()! = code)    {        modelstate.addmodelerror ("code", "Validate code is Error");        return View ();    }    Here to verify the user name, password    if (! Validatelogon (userName, password))    {        return View ();    }    Verification Success    Formsauthentication.setauthcookie (UserName, rememberme);    if (! String.IsNullOrEmpty (RETURNURL))    {        return Redirect (RETURNURL);    }    else    {        return redirecttoaction ("Index", "Home");}    }

To implement the login page, click on the picture switch verification code, you can add this JS code in the login page to implement the Refresh verification code:

<script type= "Text/javascript" src= "Http://www.cnblogs.com/Scripts/jquery-1.3.2-vsdoc.js" ></script> <script type= "Text/javascript" >    $ (function () {    $ ("#valiCode"). Bind ("click", Function () {        THIS.SRC = ". /account/getvalidatecode?time= "+ (new Date ()). GetTime ();        });        Alert ("good");    }); </script>

ASP. NET MVC implements website verification code function