C#生成隨機驗證碼

使用YZMHelper幫助類即可

using System;using System.Web;using System.Drawing;using System.Security.Cryptography;namespace PRojectWenDangManage.Framework{    /// <summary>    /// 驗證碼類    /// </summary>    public class Rand    {        #region 生成隨機數(shù)字        /// <summary>        /// 生成隨機數(shù)字        /// </summary>        /// <param name="length">生成長度</param>        public static string Number(int Length)        {            return Number(Length, false);        }        /// <summary>        /// 生成隨機數(shù)字        /// </summary>        /// <param name="Length">生成長度</param>        /// <param name="Sleep">是否要在生成前將當前線程阻止以避免重復</param>        public static string Number(int Length, bool Sleep)        {            if (Sleep) System.Threading.Thread.Sleep(3);            string result = "";            System.Random random = new Random();            for (int i = 0; i < Length; i++)            {                result += random.Next(10).ToString();            }            return result;        }        #endregion        #region 生成隨機字母與數(shù)字        /// <summary>        /// 生成隨機字母與數(shù)字        /// </summary>        /// <param name="IntStr">生成長度</param>        public static string Str(int Length)        {            return Str(Length, false);        }        /// <summary>        /// 生成隨機字母與數(shù)字        /// </summary>        /// <param name="Length">生成長度</param>        /// <param name="Sleep">是否要在生成前將當前線程阻止以避免重復</param>        public static string Str(int Length, bool Sleep)        {            if (Sleep) System.Threading.Thread.Sleep(3);            char[] Pattern = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };            string result = "";            int n = Pattern.Length;            System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));            for (int i = 0; i < Length; i++)            {                int rnd = random.Next(0, n);                result += Pattern[rnd];            }            return result;        }        #endregion        #region 生成隨機純字母隨機數(shù)        /// <summary>        /// 生成隨機純字母隨機數(shù)        /// </summary>        /// <param name="IntStr">生成長度</param>        public static string Str_char(int Length)        {            return Str_char(Length, false);        }        /// <summary>        /// 生成隨機純字母隨機數(shù)        /// </summary>        /// <param name="Length">生成長度</param>        /// <param name="Sleep">是否要在生成前將當前線程阻止以避免重復</param>        public static string Str_char(int Length, bool Sleep)        {            if (Sleep) System.Threading.Thread.Sleep(3);            char[] Pattern = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };            string result = "";            int n = Pattern.Length;            System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));            for (int i = 0; i < Length; i++)            {                int rnd = random.Next(0, n);                result += Pattern[rnd];            }            return result;        }        #endregion    }    /// <summary>    /// 驗證圖片類    /// </summary>    public class YZMHelper    {        #region 私有字段        private string text;        private Bitmap image;        private int letterCount = 4;   //驗證碼位數(shù)        private int letterWidth = 16;  //單個字體的寬度范圍        private int letterHeight = 20; //單個字體的高度范圍        private static byte[] randb = new byte[4];        private static RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();        private 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 公有屬性        /// <summary>        /// 驗證碼        /// </summary>        public string Text        {            get { return this.text; }        }        /// <summary>        /// 驗證碼圖片        /// </summary>        public Bitmap Image        {            get { return this.image; }        }        #endregion        #region 構造函數(shù)        public YZMHelper()        {            HttpContext.Current.Response.Expires = 0;            HttpContext.Current.Response.Buffer = true;            HttpContext.Current.Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1);            HttpContext.Current.Response.AddHeader("pragma", "no-cache");            HttpContext.Current.Response.CacheControl = "no-cache";            this.text = Rand.Number(4);            CreateImage();        }        #endregion        #region 私有方法        /// <summary>        /// 獲得下一個隨機數(shù)        /// </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>        /// 獲得下一個隨機數(shù)        /// </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;        }        #endregion        #region 公共方法        /// <summary>        /// 繪制驗證碼        /// </summary>        public void CreateImage()        {            int int_ImageWidth = this.text.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 < this.text.Length; int_index++)            {                _x += Next(12, 16);                _y = Next(-2, 2);                string str_char = this.text.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));            this.image = image;        }        /// <summary>        /// 字體隨機顏色        /// </summary>        public Color GetRandomColor()        {            Random RandomNum_First = new Random((int)DateTime.Now.Ticks);            Syst