验证码生成和切换

来源：互联网发布：社交网络算法编辑：程序博客网时间：2024/06/15 20:17

前端

思路：当验证码需要切换的时候，需要src的值有改变，ie浏览器才会发送请求,通过设置id变化即可。

<a href="javascript:void(0)">//表示用户点击是不会发生任何事，void表示无返回值。

<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><head>    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />    <title></title>    <script type="text/javascript">        window.onload = function () {            var validateCode = document.getElementById("validateCode");            validateCode.onclick = function () {                document.getElementById("imgCode").src = "ValidateImageCode.ashx?d="+new Date().getMilliseconds();            }        }    </script></head><body>    <form method="post" action="UserLogin.ashx">        验证码:<input type="text" name="txtCode" /><img src="ValidateImageCode.ashx" id="imgCode" />        <a href="javascript:void(0)" id="validateCode">看不清</a><br />        <input type="submit" value="登录" />    </form></body></html>

服务器ashx

思路：

创建的验证码数量和生成验证码；
验证码生成图片。

 public void ProcessRequest(HttpContext context)        {            context.Response.ContentType = "text/plain";            ValidateCode validateCode = new ValidateCode();            string code = validateCode.CreateValidateCode(4);            validateCode.CreateValidateGraphic(code, context);//context的作用        }

封装的代码

namespace Uploadfile._2017_9_03{    public class ValidateCode    {        public ValidateCode()        {        }        /// <summary>        /// 验证码的最大长度        /// </summary>        public int MaxLength        {            get { return 10; }        }        /// <summary>        /// 验证码的最小长度        /// </summary>        public int MinLength        {            get { return 1; }        }        /// <summary>        /// 生成验证码        /// </summary>        /// <param name="length">指定验证码的长度</param>        /// <returns></returns>        public string CreateValidateCode(int length)        {            int[] randMembers = new int[length];            int[] validateNums = new int[length];            string validateNumberStr = "";            //生成起始序列值            int seekSeek = unchecked((int)DateTime.Now.Ticks);            Random seekRand = new Random(seekSeek);            int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);            int[] seeks = new int[length];            for (int i = 0; i < length; i++)            {                beginSeek += 10000;                seeks[i] = beginSeek;            }            //生成随机数字            for (int i = 0; i < length; i++)            {                Random rand = new Random(seeks[i]);                int pownum = 1 * (int)Math.Pow(10, length);                randMembers[i] = rand.Next(pownum, Int32.MaxValue);            }            //抽取随机数字            for (int i = 0; i < length; i++)            {                string numStr = randMembers[i].ToString();                int numLength = numStr.Length;                Random rand = new Random();                int numPosition = rand.Next(0, numLength - 1);                validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));            }            //生成验证码            for (int i = 0; i < length; i++)            {                validateNumberStr += validateNums[i].ToString();            }            return validateNumberStr;        }        /// <summary>        /// 创建验证码的图片        /// </summary>        /// <param name="containsPage">要输出到的page对象</param>        /// <param name="validateNum">验证码</param>        public void CreateValidateGraphic(string validateCode, HttpContext context)        {            Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);            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);                //画图片的干扰线                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 Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));                //渐变.                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),                 Color.Blue, Color.DarkRed, 1.2f, true);                g.DrawString(validateCode, font, brush, 3, 2);                //画图片的前景干扰点                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);                //保存图片数据                MemoryStream stream = new MemoryStream();                image.Save(stream, ImageFormat.Jpeg);                //输出图片流                context.Response.Clear();                context.Response.ContentType = "image/jpeg";                context.Response.BinaryWrite(stream.ToArray());            }            finally            {                g.Dispose();                image.Dispose();            }        }        /// <summary>        /// 得到验证码图片的长度        /// </summary>        /// <param name="validateNumLength">验证码的长度</param>        /// <returns></returns>        public static int GetImageWidth(int validateNumLength)        {            return (int)(validateNumLength * 12.0);        }        /// <summary>        /// 得到验证码的高度        /// </summary>        /// <returns></returns>        public static double GetImageHeight()        {            return 22.5;        }    }}

阅读全文

0 0