一个MVC4 下的验证码用法

先看一个核心验证码类(不用在意实现过程,直接copy就行),下面包含了两种验证码图片(原理一样),代码如下:

using System;using System.Collections.Generic;using System.Drawing;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.IO;using System.Drawing.Imaging;namespace TyMall.Util{    public class Yzm : System.Web.UI.Page    {        #region 生成4个随机数        public string RandCode()        {            int CodeCount = 4;//生成4个随机数            string randomChar = "2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";            randomChar = randomChar.Replace(",", "");            string RandomCode = "";            System.Threading.Thread.Sleep(3);            char[] allCharArray = randomChar.ToCharArray();            int n = allCharArray.Length;            System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));            for (int i = 0; i < CodeCount; i++)            {                int rnd = random.Next(0, n);                RandomCode += allCharArray[rnd];            }            return RandomCode;        }        #endregion        #region 验证码--方式1        ///  <summary>        ///  验证码--方式1 创建验证码图片        ///  </summary>        ///  <param  name="randomcode">验证码</param>        public byte[] CreateImage(string randomcode)        {            int randAngle = 40; //随机转动角度            int mapwidth = (int)(randomcode.Length * 18);            Bitmap map = new Bitmap(mapwidth, 24);//创建图片背景            Graphics graph = Graphics.FromImage(map);            graph.Clear(Color.White);//清除画面，填充背景            //graph.DrawRectangle(new Pen(Color.Silver, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框            Random rand = new Random();            //验证码旋转，防止机器识别            char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组            //文字距中            StringFormat format = new StringFormat(StringFormatFlags.NoClip);            format.Alignment = StringAlignment.Center;            format.LineAlignment = StringAlignment.Center;            //定义颜色            Color[] c = { Color.Black, Color.Red, Color.Blue, Color.Green,                             Color.Orange, Color.Brown, Color.DarkBlue };            //画图片的背景噪音线            for (int i = 0; i < 2; i++)            {                int x1 = rand.Next(10);                int x2 = rand.Next(map.Width - 10, map.Width);                int y1 = rand.Next(map.Height);                int y2 = rand.Next(map.Height);                graph.DrawLine(new Pen(c[rand.Next(7)]), x1, y1, x2, y2);            }            for (int i = 0; i < chars.Length; i++)            {                int cindex = rand.Next(7);                int findex = rand.Next(5);                Font f = new System.Drawing.Font("Arial", 18, System.Drawing.FontStyle.Regular);//字体样式(参数2为字体大小)                Brush b = new System.Drawing.SolidBrush(c[cindex]);                Point dot = new Point(12, 16);                float angle = rand.Next(-randAngle, randAngle);//转动的度数                graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置                graph.RotateTransform(angle);                graph.DrawString(chars[i].ToString(), f, b, 1, 1, format);                graph.RotateTransform(-angle);//转回去                graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置            }            //生成图片            System.IO.MemoryStream ms = new System.IO.MemoryStream();            MemoryStream stream = new MemoryStream();            map.Save(stream, ImageFormat.Jpeg);            graph.Dispose();            map.Dispose();            return stream.ToArray();        }        #endregion        #region 验证码--方式2        /// <summary>        /// 验证码--方式2        /// </summary>        /// <param name="chkCode">验证码</param>        /// <returns></returns>        public Byte[] CreateImage2(string chkCode)        {            //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", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" };             Random rnd = new Random();            Bitmap bmp = new Bitmap(100, 40);            Graphics g = Graphics.FromImage(bmp);            g.Clear(Color.White);            //画噪线              for (int i = 0; i < 3; i++)            {                int x1 = rnd.Next(100);                int y1 = rnd.Next(40);                int x2 = rnd.Next(100);                int y2 = rnd.Next(40);                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, 18);                Color clr = color[rnd.Next(color.Length)];                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, (float)8);            }            //画噪点              for (int i = 0; i < 20; 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);            }                       MemoryStream ms = new MemoryStream();            try            {                bmp.Save(ms, ImageFormat.Png);                return ms.ToArray();            }            finally            {                //显式释放资源                  bmp.Dispose();                g.Dispose();            }        }        #endregion    }}

然后需要在控制器中实现访问的方式(其实就是写一个action,把生成的image文件返回给view)

        /// <summary>        /// 验证码,形状一        /// </summary>        /// <returns></returns>        public ActionResult Yzm()        {            TyMall.Util.Yzm sc = new TyMall.Util.Yzm();            string vVerificationCode = sc.RandCode();            Session["vcode"] = null;            Session("vcode", vVerificationCode.ToLower());   //Session中保存验证码              sc.CreateImage(vVerificationCode);            return File(sc.CreateImage(vVerificationCode), @"image/jpeg");        }        /// <summary>        ///验证码,形状二        /// </summary>        /// <returns></returns>        public ActionResult Yzm2()        {            TyMall.Util.Yzm sc = new TyMall.Util.Yzm();            string vVerificationCode = sc.RandCode();            Session["vcode"] = null;            Session("vcode", vVerificationCode.ToLower());   //Session中保存验证码              sc.CreateImage(vVerificationCode);            return File(sc.CreateImage2(vVerificationCode), @"image/jpeg");        }

view中访问方式(就是image的最原始展示方式)

<img id="yzm" src="/控制器名称/yzm" /><img id="yzm" src="/控制器名称/yzm2" />

生成如下:

OK 可以了