100 lines
3.3 KiB
C#
100 lines
3.3 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Web;
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using System.Web.Security;
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using System.Web.SessionState;
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using System.Drawing;
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using System.Drawing.Imaging;
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namespace Mtxfw.shop
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{
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/// <summary>
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/// 验证码 by Telesa 2011.04.07
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/// </summary>
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public class CheckCode : IHttpHandler, IRequiresSessionState
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{
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public void ProcessRequest(HttpContext context)
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{
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System.Web.HttpCookie hc = new HttpCookie("code");
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hc.Value = RandNum(4);
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System.Web.HttpContext.Current.Response.Cookies.Add(hc);
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ValidateCode(hc.Value, 60, 25, "Arial", 12, "#FFFFFF");
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}
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/// <summary>
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/// 生成指定位数的随机数
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/// </summary>
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/// <param name="VcodeNum">参数是随机数的位数</param>
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/// <returns>返回一个随机数字符串</returns>
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public string RandNum(int VcodeNum)
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{
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string Vchar = "0,1,2,3,4,5,6,7,8,9";
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string[] VcArray = Vchar.Split(','); //拆分成数组
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string VNum = "";
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int temp = -1; //记录上次随机数值，尽量避避免生产几个一样的随机数
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Random rand = new Random();
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//采用一个简单的算法以保证生成随机数的不同
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for (int i = 0; i < VcodeNum; i++)
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{
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if (temp != -1)
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{
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rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
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}
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int t = rand.Next(VcArray.Length - 1);
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if (temp != -1 && temp == t)
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{
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return RandNum(VcodeNum);
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}
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temp = t;
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VNum += VcArray[t];
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}
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return VNum;
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}
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/// <summary>
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/// 生成图片并写入字符
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/// </summary>
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/// <param name="VNum">目标字符</param>
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/// <param name="w">宽</param>
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/// <param name="h">高</param>
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/// <param name="font">字体文件</param>
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/// <param name="fontSize">字体大小</param>
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/// <param name="bgColor">图片背景颜色</param>
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private void ValidateCode(string VNum, int w, int h, string font, int fontSize, string bgColor)
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{
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//生成图像的实例
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Bitmap Img = new Bitmap(w, h);
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//从Img对象生成新的Graphics对象
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Graphics g = Graphics.FromImage(Img);
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//背景颜色
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g.Clear(ColorTranslator.FromHtml(bgColor));
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//生成Font类的实例
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Font f = new Font(font, fontSize, FontStyle.Italic|FontStyle.Bold);
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//生成笔刷类的实例
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SolidBrush s = new SolidBrush(Color.Red);
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//将VNum写入图片中
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g.DrawString(VNum, f, s, 3, 3);
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//将此图像以Jpeg图像文件的格式保存到流中
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Img.Save(System.Web.HttpContext.Current.Response.OutputStream, ImageFormat.Jpeg);
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System.Web.HttpContext.Current.Response.ContentType = "image/Jpeg";
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g.Dispose();
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Img.Dispose();
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System.Web.HttpContext.Current.Response.End();
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}
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public bool IsReusable
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{
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get
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{
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return false;
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}
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}
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}
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}
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