C # Good general purpose verification code

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.Drawing;4 usingSystem.Drawing.Imaging;5 usingSystem.IO;6 usingSystem.Linq;7 usingsystem.web;8 9 namespaceCascallTen { One      Public classService_code:System.Web.UI.Page A     { -         #region -          Public stringRandcode () the         { -             intCodecount =4;//generate 4 Random numbers -             stringRandomchar ="2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,j,k,l,m,n,p,q,r,s,t,u,v,w,x,y,z"; -Randomchar = Randomchar.replace (",",""); +             stringRandomcode =""; -System.Threading.Thread.Sleep (3); +             Char[] Allchararray =Randomchar.tochararray (); A             intn =allchararray.length; atSystem.Random Random =NewRandom (~unchecked((int) (DateTime.Now.Ticks)) ; -              for(inti =0; i < Codecount; i++) -             { -                 intRnd = random. Next (0, n); -Randomcode + =Allchararray[rnd]; -             } in             returnRandomcode; -         } to         #endregion +         #regionVerification Code -         ///  <summary>   the         ///Create a Captcha picture *         ///  </summary>   $         ///  <param name= "Randomcode" >Verification Code</param>  Panax Notoginseng          Public byte[] CreateImage (stringRandomcode) -         { the             intRandangle = +;//Random Rotation angle +             intMapwidth = (int) (Randomcode. Length * -); ABitmap map =NewBitmap (Mapwidth, -);//Create a picture background theGraphics graph =graphics.fromimage (map); +Graph. Clear (Color.White);//Clear the screen, fill the background -             //graph. DrawRectangle (New Pen (color.silver, 0), 0, 0, map. Width-1, map. HEIGHT-1);//Draw a border $  $Random Rand =NewRandom (); -  -             //verification code rotation to prevent machine identification the             Char[] chars = Randomcode. ToCharArray ();//splitting strings into single-character arrays -             //in text distanceWuyiStringFormat format =NewStringFormat (stringformatflags.noclip); theFormat. Alignment =Stringalignment.center; -Format. LineAlignment =Stringalignment.center; Wu             //Define Color -Color[] C ={color.black, color.red, Color.Blue, Color.green, About Color.orange, Color.brown, color.darkblue}; $  -             //draw a picture of the background noise line -              for(inti =0; I <2; i++) -             { A                 intx1 = Rand. Next (Ten); +                 intx2 = Rand. Next (map. Width-Ten, map. Width); the                 intY1 =Rand. Next (map. Height); -                 inty2 =Rand. Next (map. Height); $  theGraph. DrawLine (NewPen (C[rand. Next (7)]), x1, y1, x2, y2); the             } the  the              for(inti =0; I < chars. Length; i++) -             { in                 intCIndex = Rand. Next (7); the                 intFindex = Rand. Next (5); theFont f =NewSystem.Drawing.Font ("Arial", -, System.Drawing.FontStyle.Regular);//font Style (parameter 2 is font size) AboutBrush B =NewSystem.Drawing.SolidBrush (C[cindex]); thePoint dot =NewPoint ( A, -); the                 floatAngle = rand. Next (-randangle, Randangle);//Degrees of rotation theGraph. TranslateTransform (dot. X, Dot. Y);//move cursor to specified position + graph. RotateTransform (angle); -Graph. DrawString (Chars[i]. ToString (), F, B,1,1, format); theGraph. RotateTransform (-angle);//Turn back .BayiGraph. TranslateTransform (2,-dot. Y);//move cursor to specified position the             } the             //Create a picture -System.IO.MemoryStream ms =NewSystem.IO.MemoryStream (); -MemoryStream stream =NewMemoryStream (); the map. Save (stream, imageformat.jpeg); the graph. Dispose (); the map. Dispose (); the             returnStream. ToArray (); -  the  the         } the         #endregion  94     } the}

Front desk

1  <labelclass= "Panel-body">Verification Code:</label>2  <inputtype= "text"ID= "Yzm"name= "Yzm"class= "Form-control" />&nbsp;&nbsp;</TD>3  <imgID= "Validcode"style= "Cursor:pointer;"src= "/signin/yanzhengma"alt= "Verification Code"onclick= "this.src= '/signin/yanzhengma?time= ' + new Date (). GetTime ();" />4  <ahref="#"ID= "Changes"Data-toggle= "Modal"Data-target= "#mymodel">I can't see clearly.</a>

Js

$ ("#Changes"). Click (function () {        document.getElementById ("Validcode"). src = '/signin/yanzhengma?time= ' + new Date (). GetTime ();    });

Background call

1  /// <summary>  2         ///Generate verification Code3         /// </summary>  4         /// <returns></returns>  5          Publicactionresult Yanzhengma ()6         {7Service_code sc =NewService_code ();8             stringVverificationcode =SC. Randcode ();9session["Vcode"] =vverificationcode.tolower ();Ten            //Safe.sessionadd ("Vcode", Vverificationcode.tolower (), 2); //Save verification Code in session One SC. CreateImage (Vverificationcode); A             returnFile (SC. CreateImage (Vverificationcode),@"Image/jpeg"); -}

C # Good general purpose verification code