Verification Code Generation Method
Using System; using System. collections; using System. configuration; using System. data; using System. linq; using System. web; using System. web. security; using System. web. UI; using System. drawing; using System. drawing. imaging; using System. IO; using System. web. UI. htmlControls; using System. web. UI. webControls; using System. web. UI. webControls. webParts; using System. xml. linq; public partial class YanZhengMa: System. we B. UI. page {protected void Page_Load (object sender, EventArgs e) {// call the RndNum function to generate a four-digit verification code string str_ValidateCode = RndNum (4 ); // save it in the Session used for verification Session ["imageCode"] = str_ValidateCode; // call the CreateImage function and draw the verification code to the image CreateImage (str_ValidateCode );} private string RndNum (int VcodeNum) {string Vchar = ", a, B, c, d, e, f, g, h, I, j, k, l, m, n, o, p "+", q, r, s, t, u, v, w, x, y, z "; string [] V CArray = Vchar. split (new Char [] {','}); string VNum = ""; // int temp =-1; Random rand = new Random (); for (int I = 1; I <VcodeNum + 1; I ++) {int t = rand. next (36); VNum + = VcArray [t];} return VNum;} // generate Random Color private Color GetRandomColor () {Random RandomNum_First = new Random (int) DateTime. now. ticks); // There is nothing to say about the random number of C. threading. thread. sleep (RandomNum_First.Next (50); Random RandomN Um_Sencond = new Random (int) DateTime. now. ticks); // generate a dark int int_Red = RandomNum_First.Next (256); int int_Green = RandomNum_Sencond.Next (256 ); int int_Blue = (int_Red + int_Green> 400 )? 0: 400-int_Red-int_Green; int_Blue = (int_Blue> 255 )? 255: int_Blue; return Color. fromArgb (int_Red, int_Green, int_Blue);} public void CreateImage (string str_ValidateCode) {int int_ImageWidth = str_ValidateCode.Length * 13; Random newRandom = new Random (); // figure height: 20px Bitmap theBitmap = new Bitmap (int_ImageWidth, 20); Graphics theGraphics = Graphics. fromImage (theBitmap); // theGraphics with a white background. clear (Color. white); // The gray border theGraphics. drawRectangle (new Pen (Color. lightGray, 1), 0, 0, int_ImageWidth-1, 19); // Font of 10pt theFont = new Font ("Arial", 10 ); for (int int_index = 0; int_index <str_ValidateCode.Length; int_index ++) {string str_char = str_ValidateCode.Substring (int_index, 1); Brush newBrush = new SolidBrush (GetRandomColor ()); point thePos = new Point (int_index * 13 + 1 + newRandom. next (3), 1 + newRandom. next (3); theGraphics. drawString (str_char, theFont, newBrush, thePos);} // send the generated image back to the client MemoryStream MS = new MemoryStream (); theBitmap. save (MS, ImageFormat. jpeg); Response. clearContent (); // You Need to output the image information to modify the HTTP header Response. contentType = "image/Png"; Response. binaryWrite (ms. toArray (); theGraphics. dispose (); theBitmap. dispose (); Response. end ();}}
Part of the Code called at the front-end
View Code1 <% @ Page Language = "C #" AutoEventWireup = "true" CodeBehind = "Default. aspx. cs" Inherits = "CRM. _ Default" %>
2
3 <! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5 6 7 <title> No title page </title>
8 <script type = "text/javascript">
9 function UpdateImage ()
10 {
11 var n = Math. random ();
12 document. getElementById ("image"). src = "System/CheckCode. aspx? R = "+ n;
13}
14 </script>
15
16 <body>
17 <form id = "form1" runat = "server">
18 <div>
19
20
21
22 <a href = "javascript: UpdateImage ()"> I cannot see it clearly. Change it to another one. </a>
23
24 </div>
25 </form>
26 </body>
27
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
