MVC4 图片验证码设计

1.架构分为多层，首先说明我们实现验证码的类的位置，在这里我选择了一个公共类：Common

 

2.现在我们可以开始写验证码图片的实现方法了：

  

using System;using System.Drawing.Imaging;using System.IO;using System.Drawing;using System.Security.Cryptography;namespace Common{    /// <summary>    /// 验证图片类    /// </summary>    public static class VerifyCodeHelper    {        #region 私有字段        private static int letterCount = 4;   //验证码位数        private static int letterWidth = 16;  //单个字体的宽度范围        private static int letterHeight = 20; //单个字体的高度范围        private static byte[] randb = new byte[4];        private static RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();        private static Font[] fonts =     {       new Font(new FontFamily("Times New Roman"),10 +Next(1),System.Drawing.FontStyle.Regular),       new Font(new FontFamily("Georgia"), 10 + Next(1),System.Drawing.FontStyle.Regular),       new Font(new FontFamily("Arial"), 10 + Next(1),System.Drawing.FontStyle.Regular),       new Font(new FontFamily("Comic Sans MS"), 10 + Next(1),System.Drawing.FontStyle.Regular)    };        #endregion        #region 私有方法        /// <summary>        /// 获得下一个随机数        /// </summary>        /// <param name="max">最大值</param>        private static int Next(int max)        {            rand.GetBytes(randb);            int value = BitConverter.ToInt32(randb, 0);            value = value % (max + 1);            if (value < 0) value = -value;            return value;        }        /// <summary>        /// 获得下一个随机数        /// </summary>        /// <param name="min">最小值</param>        /// <param name="max">最大值</param>        private static int Next(int min, int max)        {            int value = Next(max - min) + min;            return value;        }        /// <summary>        /// 字体随机颜色        /// </summary>        private static Color GetRandomColor()        {            Random RandomNum_First = new Random((int)DateTime.Now.Ticks);            System.Threading.Thread.Sleep(RandomNum_First.Next(50));            Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks);            int int_Red = RandomNum_First.Next(180);            int int_Green = RandomNum_Sencond.Next(180);            int int_Blue = (int_Red + int_Green > 300) ? 0 : 400 - int_Red - int_Green;            int_Blue = (int_Blue > 255) ? 255 : int_Blue;            return Color.FromArgb(int_Red, int_Green, int_Blue);        }        /// <summary>        /// 正弦曲线Wave扭曲图片        /// </summary>        /// <param name="srcBmp">图片路径</param>        /// <param name="bXDir">如果扭曲则选择为True</param>        /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高,一般为3</param>        /// <param name="dPhase">波形的起始相位,取值区间[0-2*PI)</param>        private static System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)        {            double PI = 6.283185307179586476925286766559;            Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);            Graphics graph = Graphics.FromImage(destBmp);            graph.FillRectangle(new SolidBrush(Color.White), 0, 0, destBmp.Width, destBmp.Height);            graph.Dispose();            double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;            for (int i = 0; i < destBmp.Width; i++)            {                for (int j = 0; j < destBmp.Height; j++)                {                    double dx = 0;                    dx = bXDir ? (PI * (double)j) / dBaseAxisLen : (PI * (double)i) / dBaseAxisLen;                    dx += dPhase;                    double dy = Math.Sin(dx);                    int nOldX = 0, nOldY = 0;                    nOldX = bXDir ? i + (int)(dy * dMultValue) : i;                    nOldY = bXDir ? j : j + (int)(dy * dMultValue);                    Color color = srcBmp.GetPixel(i, j);                    if (nOldX >= 0 && nOldX < destBmp.Width                     && nOldY >= 0 && nOldY < destBmp.Height)                    {                        destBmp.SetPixel(nOldX, nOldY, color);                    }                }            }            srcBmp.Dispose();            return destBmp;        }        #endregion        #region 公共方法        /// <summary>        /// 绘制验证码        /// </summary>        public static Bitmap CreateImage(ref string randomCode)        {            Random rnd = new Random(Guid.NewGuid().GetHashCode());            for (int i = 0; i < letterCount; i++)            {                randomCode += rnd.Next(10).ToString();            }            int int_ImageWidth = randomCode.Length * letterWidth;            Bitmap image = new Bitmap(int_ImageWidth, letterHeight);            Graphics g = Graphics.FromImage(image);            g.Clear(Color.White);            for (int i = 0; i < 2; i++)            {                int x1 = Next(image.Width - 1);                int x2 = Next(image.Width - 1);                int y1 = Next(image.Height - 1);                int y2 = Next(image.Height - 1);                g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);            }            int _x = -12, _y = 0;            for (int int_index = 0; int_index < randomCode.Length; int_index++)            {                _x += Next(12, 16);                _y = Next(-2, 2);                string str_char = randomCode.Substring(int_index, 1);                str_char = Next(1) == 1 ? str_char.ToLower() : str_char.ToUpper();                Brush newBrush = new SolidBrush(GetRandomColor());                Point thePos = new Point(_x, _y);                g.DrawString(str_char, fonts[Next(fonts.Length - 1)], newBrush, thePos);            }            for (int i = 0; i < 10; i++)            {                int x = Next(image.Width - 1);                int y = Next(image.Height - 1);                image.SetPixel(x, y, Color.FromArgb(Next(0, 255), Next(0, 255), Next(0, 255)));            }            image = TwistImage(image, true, Next(1, 3), Next(4, 6));            g.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, int_ImageWidth - 1, (letterHeight - 1));            return image;        }        #endregion        #region        /// <summary>        /// 绘制验证码        /// </summary>        public static byte [] VerifyCodeBytes(ref string randomCode)        {            const int width = 120;            const int height = 35;            const int fontSize = 14;            string verifyCode = 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();            //生成验证码字符串个数             for (int i = 0; i < 6; i++)            {                verifyCode += character[rnd.Next(character.Length)];            }            //写入Session            randomCode = verifyCode;            //创建画布            Bitmap bitmap = new Bitmap(width, height);            Graphics graphics = Graphics.FromImage(bitmap);            graphics.Clear(Color.White);            //画噪线             for (int i = 0; i < 1; i++)            {                int x1 = rnd.Next(width);                int y1 = rnd.Next(height);                int x2 = rnd.Next(width);                int y2 = rnd.Next(height);                Color clr = color[rnd.Next(color.Length)];                graphics.DrawLine(new Pen(clr), x1, y1, x2, y2);            }            //画验证码字符串             for (int i = 0; i < verifyCode.Length; i++)            {                string fnt = font[rnd.Next(font.Length)];                Font ft = new Font(fnt, fontSize);                Color clr = color[rnd.Next(color.Length)];                graphics.DrawString(verifyCode[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(bitmap.Width);                int y = rnd.Next(bitmap.Height);                Color clr = color[rnd.Next(color.Length)];                bitmap.SetPixel(x, y, clr);            }            MemoryStream stream = new MemoryStream();            bitmap.Save(stream, ImageFormat.Jpeg);            return stream.ToArray();        }        #endregion    }}

3.我们在Controller里面的实现：

 

<p>using Common;using System.Web.Mvc;</p><p>namespace DhlinkOversea.Controllers{    public class AccountController : Controller    {</p><p>       </p><p>        [HttpGet]        public ActionResult VerifyCode()        {            string code = string.Empty;            byte[] bytes = VerifyCodeHelper.VerifyCodeBytes(ref code);            Session["ValidateCode"] = code;            return File(bytes, @"image/jpeg");        }</p><p> </p><p>    }}</p>

4.页面的调用：

 

<img src="@Url.Action("VerifyCode", "Account")" style="display: inline-block; vertical-align: middle; border: 1px solid #ccc; width: 120px; height: 35px; margin-left: 10px" onclick=" this.src = this.src + '?' " />

5.验证码图片的展示：