1 public class ValidateCode  2     {  3         /// <summary>  4         ///     验证码的最大长度  5         /// </summary>  6         public int MaxLength  7         {  8             get { return 10; }  9         } 10  11         /// <summary> 12         ///     验证码的最小长度 13         /// </summary> 14         public int MinLength 15         { 16             get { return 1; } 17         } 18  19         /// <summary> 20         ///     生成验证码 21         /// </summary> 22         /// <param name="length">指定验证码的长度</param> 23         /// <returns></returns> 24         public string CreateValidateCode(int length) 25         { 26             var randMembers = new int[length]; 27             var validateNums = new int[length]; 28             string validateNumberStr = ""; 29             //生成起始序列值 30             var seekSeek = unchecked((int) DateTime.Now.Ticks); 31             var seekRand = new Random(seekSeek); 32             int beginSeek = seekRand.Next(0, Int32.MaxValue - length*10000); 33             var seeks = new int[length]; 34             for (int i = 0; i < length; i++) 35             { 36                 beginSeek += 10000; 37                 seeks[i] = beginSeek; 38             } 39             //生成随机数字 40             for (int i = 0; i < length; i++) 41             { 42                 var rand = new Random(seeks[i]); 43                 int pownum = 1*(int) Math.Pow(10, length); 44                 randMembers[i] = rand.Next(pownum, Int32.MaxValue); 45             } 46             //抽取随机数字 47             for (int i = 0; i < length; i++) 48             { 49                 string numStr = randMembers[i].ToString(); 50                 int numLength = numStr.Length; 51                 var rand = new Random(); 52                 int numPosition = rand.Next(0, numLength - 1); 53                 validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1)); 54             } 55             //生成验证码 56             for (int i = 0; i < length; i++) 57             { 58                 validateNumberStr += validateNums[i].ToString(); 59             } 60             return validateNumberStr; 61         } 62  63         /// <summary> 64         ///     创建验证码的图片 65         /// </summary> 66         /// <param name="containsPage">要输出到的page对象</param> 67         /// <param name="validateNum">验证码</param> 68         public byte[] CreateValidateGraphic(string validateCode) 69         { 70             var image = new Bitmap((int) Math.Ceiling(validateCode.Length*20.0), 31); 71             Graphics g = Graphics.FromImage(image); 72             try 73             { 74                 //生成随机生成器 75                 var random = new Random(); 76                 //清空图片背景色 77                 g.Clear(Color.White); 78                 //画图片的干扰线 79                 for (int i = 0; i < 25; i++) 80                 { 81                     int x1 = random.Next(image.Width); 82                     int x2 = random.Next(image.Width); 83                     int y1 = random.Next(image.Height); 84                     int y2 = random.Next(image.Height); 85                     g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); 86                 } 87                 var font = new Font("Arial", 20, (FontStyle.Bold | FontStyle.Italic)); 88                 var brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), 89                     Color.Blue, Color.DarkRed, 1.2f, true); 90                 g.DrawString(validateCode, font, brush, 3, 2); 91                 //画图片的前景干扰点 92                 for (int i = 0; i < 100; i++) 93                 { 94                     int x = random.Next(image.Width); 95                     int y = random.Next(image.Height); 96                     image.SetPixel(x, y, Color.FromArgb(random.Next())); 97                 } 98                 //画图片的边框线 99                 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);100                 //保存图片数据101                 var stream = new MemoryStream();102                 image.Save(stream, ImageFormat.Jpeg);103                 //输出图片流104                 return stream.ToArray();105             }106             finally107             {108                 g.Dispose();109                 image.Dispose();110             }111         }112 113         /// <summary>114         ///     得到验证码图片的长度115         /// </summary>116         /// <param name="validateNumLength">验证码的长度</param>117         /// <returns></returns>118         public static int GetImageWidth(int validateNumLength)119         {120             return (int) (validateNumLength*12.0);121         }122 123         /// <summary>124         ///     得到验证码的高度125         /// </summary>126         /// <returns></returns>127         public static double GetImageHeight()128         {129             return 22.5;130         }131     }