验证码

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Web;
  5 using System.Drawing;
  6 using System.Web.SessionState;
  7 
  8 namespace MGear.UI.common
  9 {
 10     /// <summary>
 11     /// ValidateCode 的摘要说明
 12     /// </summary>
 13     public class ValidateCode : IHttpHandler, IRequiresSessionState
 14     {
 15 
 16         public void ProcessRequest(HttpContext context)
 17         {
 18             context.Response.ContentType = "image/jpeg";
 19 
 20             string code = GetRndStr();
 21 
 22             //
 23             context.Session["code"] = code;
 24 
 25             using (Bitmap img = CreateImages(code, "ch"))
 26             {
 27                 img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
 28             }
 29             //context.Response.Write("Hello World");
 30         }
 31 
 32         public bool IsReusable
 33         {
 34             get
 35             {
 36                 return false;
 37             }
 38         }
 39 
 40         /// <summary>
 41         /// 数字随机数
 42         /// </summary>
 43         /// <returns></returns>
 44         private string GetRndNum()
 45         {
 46             string code = string.Empty;
 47             Random random = new Random();
 48             for (int i = 0; i < 4; i++)
 49             {
 50                 code += random.Next(9);
 51             }
 52             return code;
 53         }
 54         /// <summary>
 55         ///  英文随机
 56         /// </summary>
 57         /// <returns></returns>
 58         private string GetRndStr()
 59         {
 60             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";
 61             string[] VcArray = Vchar.Split(‘,‘);
 62             string checkCode = string.Empty;
 63             Random rand = new Random();
 64             for (int i = 0; i < 4; i++)
 65             {
 66                 int t = rand.Next(VcArray.Length);
 67                 checkCode += VcArray[t];
 68             }
 69             return checkCode;
 70         }
 71         /// <summary>
 72         /// 中文随机
 73         /// </summary>
 74         /// <returns></returns>
 75         private string GetRndCh()
 76         {
 77             System.Text.Encoding gb = System.Text.Encoding.Default;//获取GB2312编码页（表）
 78             object[] bytes = CreateRegionCode(4);//生4个随机中文汉字编码
 79             string[] str = new string[4];
 80             System.Text.StringBuilder sb = new System.Text.StringBuilder();
 81             for (int i = 0; i < 4; i++)
 82             {
 83                 //根据汉字编码的字节数组解码出中文汉字
 84                 str[i] = gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[])));
 85                 sb.Append(str[i].ToString());
 86             }
 87             return sb.ToString();
 88         }
 89         /// <summary>
 90         /// 产生随机中文字符
 91         /// </summary>
 92         /// <param name="strlength"></param>
 93         /// <returns></returns>
 94         private static object[] CreateRegionCode(int strlength)
 95         {
 96             //定义一个字符串数组储存汉字编码的组成元素
 97             string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
 98             Random rnd = new Random();
 99             object[] bytes = new object[strlength];
100 
101             for (int i = 0; i < strlength; i++)
102             {
103                 //区位码第1位
104                 int r1 = rnd.Next(11, 14);
105                 string str_r1 = rBase[r1].Trim();
106                 //区位码第2位
107                 rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i);
108                 int r2;
109                 if (r1 == 13)
110                 {
111                     r2 = rnd.Next(0, 7);
112                 }
113                 else
114                 {
115                     r2 = rnd.Next(0, 16);
116                 }
117                 string str_r2 = rBase[r2].Trim();
118 
119                 //区位码第3位
120                 rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机种子
121                 int r3 = rnd.Next(10, 16);
122                 string str_r3 = rBase[r3].Trim();
123 
124                 //区位码第4位
125                 rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i);
126                 int r4;
127                 if (r3 == 10)
128                 {
129                     r4 = rnd.Next(1, 16);
130                 }
131                 else if (r3 == 15)
132                 {
133                     r4 = rnd.Next(0, 15);
134                 }
135                 else
136                 {
137                     r4 = rnd.Next(0, 16);
138                 }
139                 string str_r4 = rBase[r4].Trim();
140                 //定义两个字节变量存储产生的随机汉字区位码
141                 byte byte1 = Convert.ToByte(str_r1 + str_r2, 16);
142                 byte byte2 = Convert.ToByte(str_r3 + str_r4, 16);
143 
144                 //将两个字节变量存储在字节数组中
145                 byte[] str_r = new byte[] { byte1, byte2 };
146 
147                 //将产生的一个汉字的字节数组放入object数组中
148                 bytes.SetValue(str_r, i);
149             }
150             return bytes;
151         }
152         /// <summary>
153         /// 画图片的背景图+干扰线 
154         /// </summary>
155         /// <param name="checkCode"></param>
156         /// <returns></returns>
157         private Bitmap CreateImages(string checkCode, string type)
158         {
159             int step = 0;
160             if (type == "ch")
161             {
162                 step = 5;//中文字符，边界值做大
163             }
164             int iwidth = (int)(checkCode.Length * (30 + step));
165             System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 50);
166             Graphics g = Graphics.FromImage(image);
167             g.Clear(Color.White);//清除背景色
168             Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };//定义随机颜色
169             string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
170             Random rand = new Random();
171 
172             for (int i = 0; i < 50; i++)
173             {
174                 int x1 = rand.Next(image.Width);
175                 int x2 = rand.Next(image.Width);
176                 int y1 = rand.Next(image.Height);
177                 int y2 = rand.Next(image.Height);
178                 g.DrawLine(new Pen(Color.LightGray, 1), x1, y1, x2, y2);//根据坐标画线
179             }
180 
181             for (int i = 0; i < checkCode.Length; i++)
182             {
183                 int cindex = rand.Next(7);
184                 int findex = rand.Next(5);
185 
186                 Font f = new System.Drawing.Font(font[findex], 30, System.Drawing.FontStyle.Bold);
187                 Brush b = new System.Drawing.SolidBrush(c[cindex]);
188                 int ii = 4;
189                 if ((i + 1) % 2 == 0)
190                 {
191                     ii = 2;
192                 }
193                 g.DrawString(checkCode.Substring(i, 1), f, b, 15 + (i * (19 + step)), ii);
194 
195             }
196             g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1);
197             System.IO.MemoryStream ms = new System.IO.MemoryStream();
198             return image;
199         }
200     }
201 }