验证码生成类

1.一般处理程序

/// <summary>
    /// 验证码生成类
    /// </summary>
    public class verify_code : IHttpHandler, IRequiresSessionState
    {

        public void ProcessRequest(HttpContext context)
        {
            int codeW = 80;
            int codeH = 22;
            int fontSize = 16;
            string chkCode = string.Empty;
            //颜色列表，用于验证码、噪线、噪点 
            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            //字体列表，用于验证码 
            string[] font = { "Times New Roman", "Verdana", "Arial", "Gungsuh", "Impact" };
            //验证码的字符集，去掉了一些容易混淆的字符 
            char[] character = { '2', '3', '4', '5', '6', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
            Random rnd = new Random();
            //生成验证码字符串 
            for (int i = 0; i < 4; i++)
            {
                chkCode += character[rnd.Next(character.Length)];
            }
            //写入Session
            context.Session[DTKeys.SESSION_CODE] = chkCode;
            //创建画布
            Bitmap bmp = new Bitmap(codeW, codeH);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            //画噪线 
            for (int i = 0; i < 1; i++)
            {
                int x1 = rnd.Next(codeW);
                int y1 = rnd.Next(codeH);
                int x2 = rnd.Next(codeW);
                int y2 = rnd.Next(codeH);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            }
            //画验证码字符串 
            for (int i = 0; i < chkCode.Length; i++)
            {
                string fnt = font[rnd.Next(font.Length)];
                Font ft = new Font(fnt, fontSize);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 18 + 2, (float)0);
            }
            //画噪点 
            for (int i = 0; i < 100; i++)
            {
                int x = rnd.Next(bmp.Width);
                int y = rnd.Next(bmp.Height);
                Color clr = color[rnd.Next(color.Length)];
                bmp.SetPixel(x, y, clr);
            }
            //清除该页输出缓存，设置该页无缓存 
            context.Response.Buffer = true;
            context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
            context.Response.Expires = 0;
            context.Response.CacheControl = "no-cache";
            context.Response.AppendHeader("Pragma", "No-Cache");
            //将验证码图片写入内存流，并将其以 "image/Png" 格式输出 
            MemoryStream ms = new MemoryStream();
            try
            {
                bmp.Save(ms, ImageFormat.Png);
                context.Response.ClearContent();
                context.Response.ContentType = "image/Png";
                context.Response.BinaryWrite(ms.ToArray());
            }
            finally
            {
                //显式释放资源 
                bmp.Dispose();
                g.Dispose();
            }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

2.页面使用

<dl>
          <dt>验 证 码：</dt>
          <dd>
            <input id="txtCode" name="txtCode" type="text" class="input code" placeholder="输入验证码" datatype="s4-20" nullmsg="请输入右边显示的验证码" sucmsg=" " />
            <a class="send" title="点击切换验证码" href="javascript:;" onclick="ToggleCode(this, 'verify_code.ashx');return false;">
              <img src="verify_code.ashx" width="80" height="22" />
            </a>
          </dd>
</dl>

3.切换验证码

//切换验证码
function ToggleCode(obj, codeurl) {
    $(obj).children("img").eq(0).attr("src", codeurl + "?time=" + Math.random());
    return false;
}

 4.MVC生成验证码

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,out string retInfo)
        {
            //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;

            #region 字符数字随机
            //StringBuilder sbcode = new StringBuilder();
            //string strcode = "abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ23456789";

            //Random rand = new Random();
            //for (int i = 0; i < length; i++)
            //{                    
            //    sbcode.Append(strcode[rand.Next(0, strcode.Length)].ToString());
            //}
            //return sbcode.ToString();
            #endregion

            #region 验证码 +- 计算
            string retcode="";
            retInfo = "siweicn";
            int seekSeek = unchecked((int)DateTime.Now.Ticks);
            Random rand = new Random(seekSeek);         
            string stroper = "+*";
            string oper = stroper[rand.Next(0, stroper.Length)].ToString();
            string k1 = string.Empty;
            string k2 = string.Empty;

            switch (oper)
            {
                case "*":
                    {
                        k1 = rand.Next(1, 10).ToString();
                        k2 = rand.Next(1, 10).ToString();
                        retInfo = (int.Parse(k1) * int.Parse(k2)).ToString();
                        retcode = k1 + "* " + k2 + "=?";      
                        break;
                    }
                case "+":
                    {
                        k1 = rand.Next(1, 10).ToString();
                        k2 = rand.Next(1, 10).ToString();
                        retInfo = (int.Parse(k1) + int.Parse(k2)).ToString();
                        retcode = k1 + "+ " + k2 + "=?";  
                        break;
                    }
            }     
            return retcode;
            #endregion
        }
        /// <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)
        {
            //Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 13.0), 31);
            Bitmap image = new Bitmap(82, 24);
            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));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
                 Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(validateCode, font, brush, 0, 3);
                //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, 4), 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
                HttpContext.Current.Response.Clear();
                HttpContext.Current.Response.ContentType = "image/jpeg";
                HttpContext.Current.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;
        }
    }

5.控制器中创建验证码

/// <summary>
/// 获取验证码（登录页面）
/// </summary>
[AllowAnonymous]
[OutputCache(Location = OutputCacheLocation.None)]
public void VCode()
{
            var code = new ValidateCode();
            string retInfo;
            var codeStr = code.CreateValidateCode(5, out retInfo);
            Session["vcode"] = retInfo;
            code.CreateValidateGraphic(codeStr);
}

6.view页面使用验证码

<li>
    验证码：
    <input id="code" type="text" name="vcode" style="width: 116px;" placeholder="输入计算结果" />
      <img id="vcode" style="width:80px;height:22px;border:1px solid #449cde; margin-bottom:-8px; cursor:pointer"
                                     alt="验证码" title="点击刷新验证码" src="@Url.Action("VCode", "控制器名称")" />
</li>

7.点击刷新重置验证码

$("#vcode").click(function () {
     var $this = $(this);
     $this.attr("src", '@Url.Action("VCode", "控制器名称")?_=' + new Date().getTime());
})