MVC项目中验证码的使用

这是我记录验证的第二篇文章，之前还有一篇是ashx一般处理程序的。

定义类：

需要添加两个引用：System.Web、System.Drawing

//需要添加两个引用：System.Web、System.Drawing
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;

namespace Common
{
   public class ValidateCode
    {
        public ValidateCode()
        {
        }
        /// <summary>
        /// 验证码的最大长度
        /// </summary>
        public int MaxLength
        {
            get { return ; }
        }
        /// <summary>
        /// 验证码的最小长度
        /// </summary>
        public int MinLength
        {
            get { return ; }
        }
        /// <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(, Int32.MaxValue - length * );
            int[] seeks = new int[length];
            for (int i = ; i < length; i++)
            {
                beginSeek += ;
                seeks[i] = beginSeek;
            }
            //生成随机数字
            for (int i = ; i < length; i++)
            {
                Random rand = new Random(seeks[i]);
                int pownum =  * (int)Math.Pow(, length);
                randMembers[i] = rand.Next(pownum, Int32.MaxValue);
            }
            //抽取随机数字
            for (int i = ; i < length; i++)
            {
                string numStr = randMembers[i].ToString();
                int numLength = numStr.Length;
                Random rand = new Random();
                int numPosition = rand.Next(, numLength - );
                validateNums[i] = Int32.Parse(numStr.Substring(numPosition, ));
            }
            //生成验证码
            for (int i = ; i < length; i++)
            {
                validateNumberStr += validateNums[i].ToString();
            }
            return validateNumberStr;
        }
        /// <summary>
        /// 创建验证码的图片
        /// </summary>
        /// <param name="context">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), );
            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 = ; i < ; 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", , (FontStyle.Bold | FontStyle.Italic));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(, , image.Width, image.Height),
                 Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(validateCode, font, brush, , );
                //画图片的前景干扰点
                for (int i = ; i < ; 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), , , image.Width - , image.Height - );
                //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;
        }

        //C# MVC 升级版
        /// <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 byte[] CreateValidateGraphic(string validateCode)
        {
            Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), );
            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 = ; i < ; 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", , (FontStyle.Bold | FontStyle.Italic));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(, , image.Width, image.Height),
                 Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(validateCode, font, brush, , );
                //画图片的前景干扰点
                for (int i = ; i < ; 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), , , image.Width - , image.Height - );
                //保存图片数据
                MemoryStream stream = new MemoryStream();
                image.Save(stream, ImageFormat.Jpeg);
                //输出图片流
                return stream.ToArray();
            }
            finally
            {
                g.Dispose();
                image.Dispose();
            }
        }
    }
}

控制器代码：

public ActionResult ShowValidateCode()
        {
            Common.ValidateCode ValidateCode = new Common.ValidateCode();

            string code = ValidateCode.CreateValidateCode();//生成验证码，传几就是几位验证码
            Session["code"] = code;
            byte[] buffer = ValidateCode.CreateValidateGraphic(code);//把验证码画到画布

return File(buffer, "image/jpeg"); }

前端视图代码：

 <img id="img" src="/Login/ShowValidateCode/?id=1" style="float: left; height: 24px;" />

 <a href="javascript:void(0)" onclick="changeCheckCode();return false;">看不清，换一张</a>

JS代码：

function changeCheckCode() {
            $("#img").attr("src",$("#img").attr("src")+1);  //id=2
        }

写成一般处理程序

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace CZBK.ItcastProject.WebApp._2015_5_31
{
    /// <summary>
    /// ValidateImageCode 的摘要说明
    /// </summary>
    public class ValidateImageCode : IHttpHandler,System.Web.SessionState.IRequiresSessionState
    {
        //在一般处理程序中如果要使用Session必须实现.IRequiresSessionState接口.
        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            Common.ValidateCode validateCode = new Common.ValidateCode();
           string code=validateCode.CreateValidateCode();
           context.Session["validateCode"] = code;
           validateCode.CreateValidateGraphic(code,context);
        }

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