HtmlHelper of ASP. NET Image Verification code

A picture verification code of the HtmlHelper, the original calling code is as follows:

 <script language= ' javascript ' Type= "Text/javascript" > $ (document). Ready (function () {$ ("#validateCode"). Bind ("click", Function () {var url = $ (thi s). attr ("src"); URL + = "?" + math.random (); $ (this). attr ("src", url); }); }); </script>

After encapsulation into HtmlHelper:
@Html. Validatecode ()
Use the following steps:
1. Build a Verification Code helper

Using System; Using System.Collections.Generic; Using System.ComponentModel; Using System; Using System.Collections.Generic; Using System.Diagnostics.CodeAnalysis; Using System.Globalization; Using System.Linq.Expressions; Using System.Security.Policy; Using System.Text; Using System.Web; Using SYSTEM.WEB.MVC; Using System.Web.Mvc.Resources; Using System.Web.Routing; namespace MvcApplication1 {public static class Validatecodehelper {Private Const string idprefix = "Validatecode"; priva Te const int Length = 4; public static mvchtmlstring Validatecode (this htmlhelper helper) {return Validatecode (helper, idprefix);} public static Mvchtmlstring Validatecode (this htmlhelper helper,string ID) {return Validatecode (helper, ID, Length), public static Mv  Chtmlstring Validatecode (This htmlhelper helper, string id, int length) {return Validatecode (helper, id, length, null);} public static mvchtmlstring Validatecode (This htmlhelper helper, string ID, Object htmlattributes) {return ValidateCode (helper, id, Length, htmlattributes); } public static mvchtmlstring Validatecode (this htmlhelper helper, int length, object htmlattributes) {return validatecod E (helper, idprefix, length, htmlattributes);  } public static mvchtmlstring Validatecode (this htmlhelper helper, object htmlattributes) {return Validatecode (helper, 4, Htmlattributes);  } public static mvchtmlstring Validatecode (this htmlhelper helper, int length) {return Validatecode (helper,length, NULL); } public static mvchtmlstring Validatecode (this htmlhelper helper,string id,int length,object htmlattributes) {string fi Nalid = ID + "_imgvalidatecode"; var tagbuild = new Tagbuilder ("img"); Tagbuild.generateid (Finalid); var Defaultcontroller = ((Route) routetable.routes["Default"]). defaults["Controller"] + "/"; var controller = HttpContext.Current.Request.Url.Segments.Length = = 1? DEFAULTCONTROLLER:HTTPCONTEXT.CURRENT.REQUEST.URL.SEGMENTS[1]; Tagbuild.mergeattribute ("src", string. Format ("/{0}getvalidatecode?length={1}", controller,length)); Tagbuild.mergeattribute ("Alt", "Can't you see?") I'll try it! "); Tagbuild.mergeattribute ("Style", "cursor:pointer;"); Tagbuild.mergeattributes (Anonymousobjecttohtmlattributes (htmlattributes)); var sb = new StringBuilder (); Sb. Append ("<script language=\" javascript\ "type=\" text/javascript\ ">"); Sb. Append ("$ (document). Ready (function () {"); Sb. AppendFormat ("$ (\" #{0}\ "). Bind (\" Click\ ", function () {", finalid); Sb. Append ("$ (this). attr (\" style\ ", \" cursor:pointer;\ ");"); Sb. Append ("var url = $ (this)." Attr (\ "src\"); "); Sb. Append ("url + = \" &\ "+ math.random ();"); Sb. Append ("$ (this). attr (\" src\ ", url);"); Sb. Append ("});"); Sb. Append ("});"); Sb. Append ("</script>"); Return Mvchtmlstring.create (TAGBUILD+SB. ToString ()); } public static RouteValueDictionary Anonymousobjecttohtmlattributes (object htmlattributes) {var result = new RouteValue Dictionary (); if (htmlattributes! = null) {foreach (PropertyDescriptor property in Typedescriptor.getproperties (Htmlattributes)) {res Ult. ADD (property. Name.replace (' _ ', '-'), property. GetValue (htmlattributes)); }} return result; } } }

2. Generate code for CAPTCHA:

Using System; Using System.Collections.Generic; Using System.Linq; Using System.Web; Using System.Drawing; Using System.Drawing.Drawing2D; Using System.IO; Using System.Drawing.Imaging; Namespace MvcApplication1 {public class Validatecode {public Validatecode () {}//<summary>///maximum length of the verification Code///&LT  ;/summary> public int MaxLength {get {return];}///<summary>///Minimum length of verification code///</summary> public int MinLength {get {return 1;}///<summary>//Generate Verification Code///</summary>//<param name= "Length" > Specify the length of the Verification code Degrees </param>///<returns></returns> public string createvalidatecode (int length) {var randmembers = new I Nt[length]; var validatenums = new Int[length]; var validatenumberstr = ""; Generate starting sequence value var Seekseek = unchecked ((int) DateTime.Now.Ticks); var seekrand = new Random (Seekseek); var beginseek = (int) seekrand.next (0, Int32.maxvalue-length * 10000); var seeks = new Int[length]; for (var i = 0; i < length; i++) {Beginseek + =10000; Seeks[i] = Beginseek; }//Generate random numbers for (var i = 0; i < length; i++) {var rand = new Random (Seeks[i]), var pownum = 1 * (int) Math.pow (lengt h); Randmembers[i] = rand. Next (Pownum, Int32.MaxValue); }//extract random numbers for (var i = 0; i < length; i++) {var numstr = randmembers[i]. ToString (); var numlength = numstr.length; var rand = new Random (); var numposition = rand. Next (0, numLength-1); Validatenums[i] = Int32.Parse (numstr.substring (numposition, 1)); }//Generate Verification code for (var i = 0; i < length; i++) {validatenumberstr + = Validatenums[i]. ToString (); } return VALIDATENUMBERSTR; }///<summary>//Create a picture of the captcha///</summary>//<param name= "Validatecode" > Verification Code </param> public byt E[] Createvalidategraphic (string validatecode) {var image = new Bitmap ((int) math.ceiling (validatecode.length * 12.0), 22 ); var g = graphics.fromimage (image);  try {//Generate random generator var random = new Random ();//empty the picture background color g.clear (color.white);//Draw the image of the interference line for (int i = 0; i <; i++) {var X1 = RanDom. Next (image. Width); var x2 = random. Next (image. Width); var y1 = random. Next (image. Height); var y2 = random. Next (image. Height); G.drawline (New Pen (color.silver), x1, y1, x2, y2); }//font Font = new Font ("Arial", page, (FontStyle.Bold | Fontstyle.italic)); String[] FontName = {"Chinese new Wei", "Song Body", "round Body", "blackbody", "Official Script"}; var font = new Font (fontname[new Random (). Next (0, Validatecode.length)], A, (FontStyle.Bold | Fontstyle.italic)); var 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); Picture the foreground interference point for (var i = 0; i < i++) {var x = random. Next (image. Width); var 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 var stream = new MemoryStream (); Image. Save (stream, imageformat.jpeg); Output picture stream return stream. ToArray (); } finally {g.dispose (); IMage. Dispose (); }}///<summary>///Get the length of the CAPTCHA picture///</summary>//<param name= "Validatenumlength" > The length of the verification code </param& Gt <returns></returns> public static int getimagewidth (int validatenumlength) {return (int) ( Validatenumlength * 12.0); }///<summary>///Get the height of the verification code///</summary>//<returns></returns> public static double Getimageh Eight () {return 23;}} }

3. Build a Basecontroller

Using System; Using System.Collections.Generic; Using System.Linq; Using System.Web; Using SYSTEM.WEB.MVC;  Namespace MvcApplication1 {public class Basecontroller:controller {public actionresult getvalidatecode (int length) {var Vcode = new Validatecode (); var code = vcode.createvalidatecode (length); session["Validatecode"] = code; var bytes = vcode.createvalidategraphic (code); Return File (bytes, @ "Image/gif"); } protected String Getvalidatecode () {return session["Validatecode"]. ToString (); } } }

4. Let controller inherit Basecontroller:

Using System; Using System.Collections.Generic; Using System.Linq; Using System.Web; Using SYSTEM.WEB.MVC; Using System.Web.Security; Namespace Mvcapplication1.controllers {public class Homecontroller:basecontroller {public ActionResult Index () {VIEWBA G.message = "Welcome to ASP. mvc!"; return View (); } public ActionResult about () {var code = Getvalidatecode (); return View ();}} }

5. Page Call Code:

@using MvcApplication1 @{viewbag.title = "About Us",} 
6. Verification Code: