生成中文验证码 生成汉字验证码

直接上代码：

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Text;  //添加引用using System.Drawing;  //添加引用namespace WebApplication3{    public partial class WebForm4 : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            GraphicsImage();        }        private object[] CreateString()        {            //定义一个数组存储汉字编码的组成元素            string[] str = new string[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };            Random ran = new Random();  //定义一个随机数对象            object[] bytes = new object[4];            for (int i = 0; i < 4; i++)            {                //获取区位码第一位                int ran1 = ran.Next(11, 14);                string str1 = str[ran1].Trim();                //获取区位码第二位并防止数据重复                ran = new Random(ran1 * unchecked((int)DateTime.Now.Ticks) + i);                int ran2;                if (ran1 == 13)                {                    ran2 = ran.Next(0, 7);                }                else                {                    ran2 = ran.Next(0, 16);                }                string str2 = str[ran2].Trim();                //获取区位码第三位                ran = new Random(ran2 * unchecked((int)DateTime.Now.Ticks) + i);                int ran3 = ran.Next(10, 16);                string str3 = str[ran3].Trim();                //获取区位码第四位                ran = new Random(ran3 * unchecked((int)DateTime.Now.Ticks) + i);                int ran4;                if (ran3 == 10)                {                    ran4 = ran.Next(1, 16);                }                else if (ran3 == 15)                {                    ran4 = ran.Next(0, 15);                }                else                {                    ran4 = ran.Next(0, 16);                }                string str4 = str[ran4].Trim();                //定义字节变量存储产生的随机汉字区位码                byte byte1 = Convert.ToByte(str1 + str2, 16);                byte byte2 = Convert.ToByte(str3 + str4, 16);                byte[] stradd = new byte[] { byte1, byte2 };                //将产生的汉字字节放入数组                bytes.SetValue(stradd, i);            }            return bytes;        }        private string GetString()        {            Encoding gb = Encoding.GetEncoding("gb2312");            object[] bytes = CreateString();            //根据汉字字节解码出中文汉字            string str1 = gb.GetString((byte[])Convert.ChangeType(bytes[0], typeof(byte[])));            string str2 = gb.GetString((byte[])Convert.ChangeType(bytes[1], typeof(byte[])));            string str3 = gb.GetString((byte[])Convert.ChangeType(bytes[2], typeof(byte[])));            string str4 = gb.GetString((byte[])Convert.ChangeType(bytes[3], typeof(byte[])));            string str = str1 + str2 + str3 + str4;            HttpContext.Current.Response.Cookies.Add(new HttpCookie("CheckCode", str));            return str;        }        public void GraphicsImage()        {            System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((GetString().Length * 22.5)), 22);            Graphics g = Graphics.FromImage(image);  //创建画布            try            {                //生成随机生成器                Random random = new Random();                //清空图片背景色                g.Clear(Color.White);                //画图片的背景噪音线                for (int i = 0; i < 1; 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.Black), x1, y1, x2, y2);                }                Font font = new System.Drawing.Font("Couriew New", 12, System.Drawing.FontStyle.Bold);                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush                    (new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);                g.DrawString(GetString(), font, brush, 2, 2);                //画图片的前景噪音点                for (int i = 0; i < 50; 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), 0, 0, image.Width - 1, image.Height - 1);                System.IO.MemoryStream ms = new System.IO.MemoryStream();                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);                                Response.ClearContent();                Response.ContentType = "image/Gif";                Response.BinaryWrite(ms.ToArray());            }            catch (Exception ms)            {                Response.Write(ms.Message);            }        }    }}

结果：