Login.html
1 <!DOCTYPE html> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> 5 <title></title> 6 </head> 7 <body> 8 <table> 9 <tr> 10 <td>用户名：</td> 11 <td><input type="text" /></td> 12 </tr> 13 <tr> 14 <td>密码：</td> 15 <td><input type="password" /></td> 16 </tr> 17 <tr> 18 <td>验证码</td> 19 <td><img src="ValidCode.ashx" /></td> 20 </tr> 21 <tr></tr> 22 </table> 23 </body> 24 </html>
ValidCode.ashx
1 <%@ WebHandler Language="C#" Class="ValidCode" %> 2 3 using System; 4 using System.Web; 5 using System.Drawing; 6 7 public class ValidCode : IHttpHandler 8 { 9 10 public void ProcessRequest(HttpContext context) 11 { 12 context.Response.ContentType = "image/jpeg"; 13 //生成随机验证码的字符串 14 string code = MakeRanStr(); 15 using (Image img = new Bitmap(100, 26)) 16 { 17 using (Graphics g = Graphics.FromImage(img)) 18 { 19 //背景为白色 20 g.Clear(Color.White); 21 //验证码边框 22 g.DrawRectangle(Pens.Black, new Rectangle(0, 0, img.Width - 1, img.Height - 1)); 23 //干扰线 24 DrwaGanRaoXian(50, g, img); 25 g.DrawString(code, new Font("微软雅黑", 12), Brushes.Red, 1, 2); 26 } 27 img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); 28 } 29 } 30 31 /// <summary> 32 /// 画干扰线 33 /// </summary> 34 void DrwaGanRaoXian(int count, Graphics g, Image img) 35 { 36 Random ran = new Random(); 37 for (int i = 0; i < count; i++) 38 { 39 Point p1 = new Point(ran.Next(img.Width), ran.Next(img.Height)); 40 Point p2 = new Point(p1.X - ran.Next(-50, 50), p1.Y - ran.Next(-50, 50)); 41 g.DrawLine(Pens.Black, p1, p2); 42 } 43 } 44 45 /// <summary> 46 /// 生成随机码 47 /// </summary> 48 /// <returns></returns> 49 string MakeRanStr() 50 { 51 char[] charArr = new char[10] { 'a', 'b', 'c', '1', '2', '3', '你', '好', '啊', '呀' }; 52 string strValidCode = ""; 53 Random ran = new Random(); 54 int index = 0; 55 for (int i = 0; i < 5; i++) 56 { 57 index = ran.Next(9); 58 strValidCode += charArr[index]; 59 } 60 return strValidCode; 61 } 62 63 public bool IsReusable 64 { 65 get 66 { 67 return false; 68 } 69 } 70 71 }