c# 识别验证码

using System;
using System.Collections.Generic;
using System.Text;

using System.Net;
using System.Web;
using System.Drawing;
using System.Drawing.Imaging;

namespace PcRegister
{
    /**//// <summary>
    /// CrMonterNetImg 的摘要说明。
    /// </summary>
    public class CrMonterNetImg
    {
        /**//// <summary>
        /// Cookie集合，使用这个cookie集合去获取验证码
        /// </summary>
        private CookieCollection Cookie=null;

        /**//// <summary>
        /// 验证码的地址
        /// </summary>
        private string ImgUrl="";

        /**//// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="StrUrl">验证码地址</param>
        /// <param name="Cookies">cookie集合</param>
        public CrMonterNetImg(string StrUrl, CookieCollection Cookies)
        {
            this.ImgUrl = StrUrl;
            this.Cookie = Cookies;
        }

        private bool _debug=false;
        /**//// <summary>
        /// 设置是否为debug，如果是debug的话，就把当前图片保存到c:
.bmp
        /// </summary>
        public bool debug
        {
            set
            {
                _debug=value;
            }
            get
            {
                return _debug;
            }
        }

        /**//// <summary>
        /// 识别主函数
        /// </summary>
        /// <returns></returns>
        public string proc()
        {
            //图形
            Bitmap bmp=null;
            //保存深浅2种颜色
            Color[] cc = new Color[2];
            int[] left = new int[5];//左边的点
            int[] right = new int[5];//右边的点
            int[] top = new int[5];//顶点
            int[] bottom = new int[5];//底点
            string str = "";
            try
            {
                int i=0;
                // '抓取图片
                while (i != 4)
                {//一直抓到图形中有4个独立的字符

                    bmp = this.crImg();
                    if(debug)
                    {
                        bmp.Save(@"c:\1.bmp");
                    }
                    cc = this.GetDeepColor(bmp);//得到深浅颜色
                    this.FormatImg(bmp, cc);//格式话图形，去掉背景
                    Array array1 = this.GetV(bmp);//得到x轴上有黑色点的坐标
                    i = this.chkImg(array1, ref left, ref right);//分析字符个数
                }
                //这里分析单个字符的上下左右点，这样就可以确定范围了
                this.getTB(bmp, left , right, ref top, ref bottom);

                //识别出来
                str = this.crImg(bmp, left, right, top, bottom);

                //释放资源
                bmp.Dispose();
            }
            catch (Exception exception2)
            {
                //ProjectData.SetProjectError(exception2);
                Exception exception1 = exception2;
                //ProjectData.ClearProjectError();
            }
            finally
            {//释放资源
                if (bmp != null)
                {
                    bmp.Dispose();
                }
            }
            return str;
        }

        //其他辅助函数#region 其他辅助函数
        /**//// <summary>
        /// 加载验证码
        /// </summary>
        /// <returns>验证码图形</returns>
        private Bitmap crImg()
        {
            Bitmap bmp=null;
            //响应
            HttpWebResponse response=null;
            try
            {
                //请求
                HttpWebRequest request = (HttpWebRequest) WebRequest.Create(this.ImgUrl);

                //这里附加cookie
                request.CookieContainer = new CookieContainer();
                if (this.Cookie != null)
                {
                    request.CookieContainer.Add(this.Cookie);
                }
                //得到响应
                response = (HttpWebResponse) request.GetResponse();
                //从响应流直接创建图片
                bmp = new Bitmap(response.GetResponseStream());
            }
            catch
            {
            }
            finally
            {//清理资源
                if (response != null)
                {
                    response.Close();
                }
            }
            return bmp;
        }

 
        /**//// <summary>
        /// "得到垂直投影"，就是得到字符在y轴上有的点
        /// </summary>
        /// <param name="img">图形</param>
        /// <returns>返回这些点所在的array</returns>
        private Array GetV(Bitmap img)
        {
            string str = "";
    
            for (int i = 0; i <= img.Width - 1; i++)
            {//在图形的x轴上进行循环
                
                //然后在y轴上找黑点
                for (int h = 0; h <= img.Height - 1; h++)
                {
                    Color c = img.GetPixel(i, h);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {//如果找到一个黑点的话，就把这个x轴的坐标给记忆下来。
                        str = str + "," + i.ToString();
                        break;
                    }
                }
            }
            if (str.Length > 0)
            {//因为上面采用连接的方式，所以第一个字符可能是“,”，这里去掉
                str = str.Substring(1);
            }
            return str.Split(new char[] { ',' });
        }

        /**//// <summary>
        /// 查找单个字符中图形中最上和最下的黑点。
        /// </summary>
        /// <param name="Img">图形</param>
        /// <param name="IntS">四个字符的左边点</param>
        /// <param name="IntE">四个字符的右边点</param>
        /// <param name="T">传出参数：保存四个字符顶点</param>
        /// <param name="B">传出参数：保存四个字符底点</param>
        /// <returns></returns>
        private object getTB(Bitmap Img, int[] IntS, int[] IntE, ref int[] T, ref int[] B)
        {
            //用来计数，最多四个数字。
            int i = 0;
            while (true)
            {//一个循环处理一个图形
    
                for (int w = IntS[i]; w <= IntE[i]; w++)
                {//对其中的一个字符从左到右开始找
                    int h = 0;
                    do
                    {//然后在上面指定的范围内查找最上黑点和最下黑点的位置
                        Color c1 = Img.GetPixel(w, h);
                        if (c1.ToArgb() == Color.Black.ToArgb())
                        {
                            if (T[i] == 0)
                            {
                                T[i] = h;
                            }
                            if (h < T[i])
                            {
                                T[i] = h;
                            }
                            if (h > B[i])
                            {
                                B[i] = h;
                            }
                        }
                        h++;
                    }
                    while (h <= 0x13);
                }

                i++;
                if (i > 3)
                {
                    return null;
                }
            }

        }

        /**//// <summary>
        /// 得到深色、浅色--深色的RGB刚好相差30
        /// </summary>
        /// <param name="Img"></param>
        /// <returns></returns>
        private Color[] GetDeepColor(Bitmap Img)
        {
            Color c=Color.White;//深色
            Color c1=Color.White;//浅色
            Color[] cc = new Color[3];
            if (Img == null)
            {//检查图片是否有效
                return null;
            }
        
            for (int w = 0; w <= Img.Width - 1; w++)
            {//从做到右开始找。
                int h = 4;
                do
                {//经过观察，y方向4-6坐标的三行绝对可以找到这2种颜色

                    Color temp = Img.GetPixel(w, h);// 当前色
                    if (temp.R < 0xff)
                    {//'有颜色的时候才在处理
                        if (c.R > 0)
                        {
                            //用找到的颜色和当前颜色比较
                            //'如果找到的颜色比当前颜色要小
                            // '那么 c就是深色
                            // 'c1就是浅色
                            if (c.R < temp.R)
                            {
                                c1 = temp;
                            }
                            if (c.R > temp.R)
                            {
                                c1 = c;
                                c = temp;
                            }
                        }
                        else
                        {
                            c = temp;
                        }
                        if (c1.ToArgb() > 0)
                        {
                            break;
                        }
                    }
                    h++;
                }
                while (h <= 6);
            }
            cc[0] = c;
            cc[1] = c1;
            return cc;
        }

        /**//// <summary>
        /// 去背景，单色显示
        /// </summary>
        /// <param name="Img"></param>
        /// <param name="Cc"></param>
        /// <returns></returns>
        private object FormatImg(Bitmap Img, Color[] Cc)
        {
            object obj=null;
    
            //循环处理每一点
            for (int w = 0; w <= Img.Width - 1; w++)
            {            
                for (int h = 0; h <=  Img.Height - 1; h++)
                {
                    //如果当前颜色是深色的话，就转化成黑色
                    //否则就转化成白色
                    Color c = Img.GetPixel(w, h);
                    if (c.ToArgb() == Cc[1].ToArgb())
                    {
                        Img.SetPixel(w, h, Color.White);
                    }
                    if (c.ToArgb() == Cc[0].ToArgb())
                    {
                        Img.SetPixel(w, h, Color.Black);
                    }
                }
            }
            return obj;
        }

        /**//// <summary>
        /// 识别图形的字符
        /// </summary>
        /// <param name="Img">图形</param>
        /// <param name="IntS">计算出来的左边点</param>
        /// <param name="Inte">计算出来的上面点</param>
        /// <param name="T">计算出来的上面点</param>
        /// <param name="B">计算出来的顶点</param>
        /// <returns>字符</returns>
        private string crImg(Bitmap Img, int[] IntS, int[] Inte, int[] T, int[] B)
        {
            string str = "";
            int i = 0;
            do
            {//依次处理4个字符

                //获取当前范围：四个构造函数分别是x,y ，宽和高，已经可以确定字符的范围了。
                Rectangle r = new Rectangle(IntS[i], T[i], (Inte[i] - IntS[i]) + 1, (B[i] - T[i]) + 1);
                //裁减出来的图形
                Bitmap bmp = Img.Clone(r, Img.PixelFormat);
                //识别并保存出来
                str = str + this.crImg(bmp);
                //释放当前图片资源
                bmp.Dispose();

                //处理下一个。
                i++;
            }
            while (i <= 3);
            return str;
        }

   

        /**//// <summary>
        /// 检测当前的图片是否符合社识别条件，通过分析字符数量
        /// </summary>
        /// <param name="Va"></param>
        /// <param name="IntS">ref：用来保存四个字符的左边点</param>
        /// <param name="IntE">ref：用来保存四个字符的右边点</param>
        /// <returns>字符数量</returns>
        private int chkImg(Array Va, ref int[] intS, ref int[] intE)
        {
            int IntRang=0; //一共找到多少段

            string[] str = (string[]) Va;
            intS = new int[] { -1, -1, -1, -1, -1, -1, -1 };  //保存段的开始数字,多申请几个，避免出问题
            intE = new int[] { -1, -1, -1, -1, -1, -1, -1 };  //保存段的结束数字,多申请几个，避免出问题
 
            for (int i = 0; i <= str.Length - 2; i++)
            {
                int intCur = int.Parse(str[i]);//当前坐标
                int IntPrew = int.Parse(str[i + 1]);//下一个坐标
                if ((IntPrew - intCur) == 1)
                {//如果2个数字相差一，表示这个数字还是连续的

                    if (intS[IntRang] == -1)
                    {//如果已经找到结尾了
                        intS[IntRang] = intCur;
                    }
                    if (i == (str.Length - 2))
                    { //如果到了倒数第二数字，最后一个数字就是结束了
                        intE[IntRang] = IntPrew;
                    }
                }
                else
                {
                    intE[IntRang] = intCur;
                    IntRang++;
                }
            }
            return (IntRang + 1);
        }

 
        /**//// <summary>
        /// 识别小图片中的数字
        /// </summary>
        /// <param name="Img">小图形</param>
        /// <returns>识别出来的字符</returns>
        private string crImg(Bitmap Img)
        {
            if (Img != null)
            {//检查图片
                Color c;

                if ((Img.Width == 6) & (Img.Height == 9))
                {//宽6 高9的一定是1
                    return "1";
                }

                if ((Img.Width == 9) & (Img.Height == 12))
                {//宽9 高12的一定是4
                    return "4";
                }

                if ((Img.Width == 8) & (Img.Height == 9))
                {//如果宽是8 高是9的话

                    //找特殊点
                    Color c2 = Img.GetPixel(0, 1);
                    if (c2.ToArgb() == Color.Black.ToArgb())
                    {//如果0，1是黑点的话，就是2，否则就是0
                        return "2";
                    }
                    return "0";
                }

                if ((Img.Width == 8) & (Img.Height == 11))
                {//宽8  高11
                    c = Img.GetPixel(2, 0);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {//也同样找特殊点来区分2.0
                        return "8";
                    }
                    return "6";
                }
                if ((Img.Width == 8) & (Img.Height == 12))
                {//同上的方法区分3.5.7.9
                    //都可以使用特殊点来区分
                    c = Img.GetPixel(5, 2);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {
                        return "3";
                    }
                    c = Img.GetPixel(2, 4);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {
                        return "5";
                    }
                    c = Img.GetPixel(0, 0);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {
                        return "7";
                    }
                    c = Img.GetPixel(0, 5);
                    if (c.ToArgb() == Color.Black.ToArgb())
                    {
                        return "9";
                    }
                }
            }
            return " ";
        }
     
    }
}