一个简单的又好看的验证码

来源：互联网发布：python中判断数据类型编辑：程序博客网时间：2024/04/29 12:27

自己在项目中经常使用的验证码，样式还不错，简单又好用，为了以后方便，写入博客以便以后使用查看

写一个一般处理程序checkcode.ashx，返回生成的验证码

using System;using System.Collections.Generic;using System.Drawing;using System.Linq;using System.Web;using System.Web.SessionState;namespace VIPSite{    /// <summary>    /// checkcode 的摘要说明    /// </summary>    public class checkcode : IHttpHandler,IRequiresSessionState    {        HttpContext context;        public void ProcessRequest(HttpContext context1)        {                       this.context = context1;            CreateCheckCodeImage(GenerateCheckCode());        }        public bool IsReusable        {            get            {                return false;            }        }        private string GenerateCheckCode()        {            int number;            char code;            string checkCode = String.Empty;            System.Random random = new Random();            for (int i = 0; i < 5; i++)            {                number = random.Next();                if (number % 2 == 0)                    code = (char)('0' + (char)(number % 10));                else                    code = (char)('A' + (char)(number % 26));                checkCode += code.ToString();            }            context.Session["chkcode"] = checkCode;            return checkCode;        }        private void CreateCheckCodeImage(string checkCode)        {            if (checkCode == null || checkCode.Trim() == String.Empty)                return;            Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 20.5)), 32);            Graphics g = Graphics.FromImage(image);            try            {                //生成随机生成器                Random random = new Random();                //清空图片背景色                g.Clear(Color.White);                //画图片的背景噪音线                for (int i = 0; i < 25; i++)                {                    int x1 = random.Next(image.Width);                    int x2 = random.Next(image.Width);                    int y1 = random.Next(image.Height);                    int y2 = random.Next(image.Height);                    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);                }                Font font = new System.Drawing.Font("Arial", 20, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(3, 3, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);                g.DrawString(checkCode, font, brush, 2, 2);                //画图片的前景噪音点                for (int i = 0; i < 100; i++)                {                    int x = random.Next(image.Width);                    int y = random.Next(image.Height);                    image.SetPixel(x, y, Color.FromArgb(random.Next()));                }                //画图片的边框线                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);                System.IO.MemoryStream ms = new System.IO.MemoryStream();                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);                context.Response.ClearContent();                context.Response.ContentType = "image/Gif";               context.Response.BinaryWrite(ms.ToArray());            }            finally            {                g.Dispose();                image.Dispose();            }        }    }}

在前台页面中使用

<script type="text/javascript">        function changeCode() {            document.getElementById("imgCode").src = "/ashx/checkcode.ashx?d=" + new Date().getMilliseconds();        }    </script><img src="/ashx/checkcode.ashx" id="imgCode" onclick="return changeCode()" />

后台判断

if (Session["chkcode"] == null)                {                    string script = "alert('验证码已过期，请重新刷新页面!');location='" + ConfigHelper.Domain + "/lg";                    PageHelper.RegScript(Page, script);                    return;                }                if (txtcode.Text.Trim().ToLower() != Session["chkcode"].ToString().ToLower())                {                    string script = "alert('验证码不正确，请重新输入!');";                    PageHelper.RegScript(Page, script);                }                else                {                    Session.Remove("chkcode");                }

验证码图片展示

至此一个完整的验证码的功能就完成了

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