这些东西网上都泛滥了，随便拉了个过来，然后改改，加上自己的标示什么的，就是这样子了。
可以定义验证码的格式，包括字母、数字、特殊符号和汉字，指定生成的图片大小。
本来还想加上图片扭曲的，可怕以后用起来被人说“万恶的验证码”所以就算了。
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using
System;
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using
System.Collections;
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using
System.Collections.Generic;
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using
System.Drawing;
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using
System.Text;
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using
System.Threading;
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using
System.Drawing.Drawing2D;
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9
namespace
SHNK.Framework.Utility
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{ 11 /**//// <summary> 12 /// 验证码生成类 13 /// </summary> 14 public static class ValidateCodeHelper 15 { 16 /**//// <summary> 17 /// 生成长度为length、字符类型为codeType的验证码字符串 18 /// </summary> 19 /// <param name="codeType">验证码类型</param> 20 /// <param name="length">验证码长度</param> 21 /// <returns>验证码字符串</returns> 22 public static string GenerateCode(ValidateCodeType codeType, int length) 23 { 24 25 const string sNumber = "0123456789"; 26 const string sLetter = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; 27 const string sSymbol = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"; 28 29 if ((codeType | ValidateCodeType.Chinese) == codeType) 30 { 31 return GetChinese(length); 32 } 33 34 StringBuilder blocks = new StringBuilder(); 35 StringBuilder builder = new StringBuilder(); 36 37 if ((codeType | ValidateCodeType.Number) == codeType) 38 blocks.Append(sNumber); 39 40 if ((codeType | ValidateCodeType.Letter) == codeType) 41 blocks.Append(sLetter); 42 43 if ((codeType | ValidateCodeType.Symbol) == codeType) 44 blocks.Append(sSymbol); 45 46 Random rand = new Random(); 47 for (int i = 0; i < length; i++) 48 { 49 builder.Append(blocks[rand.Next(blocks.Length)]); 50 } 51 52 return builder.ToString(); 53 } 54 55 /**//// <summary> 56 /// 获取num个中文字符 57 /// </summary> 58 /// <param name="num">字符串长度</param> 59 /// <returns>中文字符</returns> 60 private static string GetChinese(int num) 61 { 62 /**//* ********************************************* 63 * be in common use 64 * 65 * first byte 0xB0 - 0xD7 66 * second byte 0xA1 - 0xFE 67 * 68 * except 0xD7FA - 0xD7FE (space) 69 * *********************************************/ 70 const int _MAX_SIZE = 3755; // (0xD7 - 0xB0 + 1) * (0xFE - 0xA1 + 1) - (0xD7FE - 0xD7FA + 1); 71 const int _Capacity = 94; // 0xFE - 0xA1 + 1 72 73 Random rand = new Random(); 74 StringBuilder builder = new StringBuilder(); 75 for (int i = 0; i < num; i++) 76 { 77 int index = rand.Next(_MAX_SIZE); 78 int high = Math.Floor(index.ToDouble() / _Capacity.ToDouble()).ToInt32(); 79 int lower = index % _Capacity; 80 string code = Encoding.Default.GetString(new byte[] { (byte)(high + 0xB0), (byte)(lower + 0xA1) }); 81 builder.Append(code); 82 } 83 return builder.ToString(); 84 } 85 86 /**//// <summary> 87 /// 按照输入的字符串src和每个字符位图的宽度生成一张图片 88 /// </summary> 89 /// <param name="src">验证码</param> 90 /// <param name="height">图片高度</param> 91 /// <param name="wdpc">每个字符所占宽度</param> 92 /// <returns>验证图片</returns> 93 public static Image GenerateImage(string src, int height, int wdpc) 94 { 95 Bitmap img = new Bitmap(src.Length * wdpc, height); 96 Graphics g = Graphics.FromImage(img); 97 g.Clear(Color.White); 98 99 Random rand = new Random();100 for (int i = 0; i < 25; i++)101 {102 int x1 = rand.Next(img.Width);103 int x2 = rand.Next(img.Width);104 int y1 = rand.Next(img.Height);105 int y2 = rand.Next(img.Height);106107 g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);108 }109 Font f = new Font("'Segoe UI' 微软雅黑 Verdana 宋体", 14f);110 Brush b = new LinearGradientBrush(new Rectangle(new Point(0, 0), img.Size), Color.Blue, Color.DarkRed, LinearGradientMode.ForwardDiagonal);111 for (int i = 0; i < src.Length; i++)112 g.DrawString(src[i].ToString(), f, b, wdpc * i.ToSingle(), 0f);113114 g.Save();115 for (int i = 0; i < 100; i++)116 {117 int x = rand.Next(img.Width);118 int y = rand.Next(img.Height);119120 img.SetPixel(x, y, Color.FromArgb(rand.Next()));121 }122123 return img;124 }125 }126127 ValidateCodeType Enum#region ValidateCodeType Enum128 /**//// <summary>129 /// 验证码类型枚举130 /// </summary>131 public enum ValidateCodeType132 {133 /**//* ValidateCodeType枚举成员 134 * 135 * Number:136 * ASCII Code 48 - 57137 * 138 * Letter:139 * Uppercase140 * ASCII Code 65 - 90141 * Lowercase142 * ASCII Code 97 - 122143 * 144 * Symbol:145 * ASCII Code 33 - 126 except Number and Letter146 * 147 * Chinese:148 * Unicode 0xA1A1-0xF7FE149 */150 /**//// <summary>151 /// 数字152 /// </summary>153 Number = 1,154 /**//// <summary>155 /// 字母156 /// </summary>157 Letter = 2,158 /**//// <summary>159 /// 符号160 /// </summary>161 Symbol = 4,162 /**//// <summary>163 /// 汉字164 /// </summary>165 Chinese = 8166 }167 #endregion168169 public static partial class Extension170 {171 convert method#region convert method172 public static double ToDouble(this IConvertible o)173 {174 return Convert.ToDouble(o);175 }176177 public static int ToInt32(this IConvertible o)178 {179 return Convert.ToInt32(o);180 }181182 public static float ToSingle(this IConvertible o)183 {184 return Convert.ToSingle(o);185 }186 #endregion187 }188}
转载于:https://www.cnblogs.com/HappyQQ/archive/2008/04/16/1155945.html
