生成验证码（纯中文）

下面我来写一个生成纯中文的验证码技术，写一个类库。

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Text;  //添加引用

using System.Drawing;  //添加引用

/// <summary>

/// CheckCode_Ch 的摘要说明

/// </summary>

public class CheckCode_Ch

{

    public CheckCode_Ch()

    {

        //

        // TODO: 在此处添加构造函数逻辑

        //

    }

    private static 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 static 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 static 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);

            HttpContext.Current.Response.ClearContent();

            HttpContext.Current.Response.ContentType = "image/Gif";

            HttpContext.Current.Response.BinaryWrite(ms.ToArray());

        }

        catch (Exception ms)

        {

            HttpContext.Current.Response.Write(ms.Message);

        }



    }





}

第二步建立一个页面引用类库ChineseCheckCode.aspx前台不用写代码，后台引用类库。。

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;





public partial class UserValidator_ChineseCheckCode : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        CheckCode_Ch.GraphicsImage();  //调用方法生成四位汉字验证码

    }

}

第三步引用验证码页

                          <asp:TextBox ID="Validator" runat="server" Width="150px" ></asp:TextBox>          

                          <img id="Img1" alt="看不清，请点击我！" onclick="this.src=this.src+'?'" src="ChineseCheckCode.aspx"

                                        style="width: 75px; height: 24px" align="left" />

                            <asp:ImageButton ID="imgBtnLogin" runat="server" ImageUrl="~/Images/Login.GIF" 

                            OnClick="imgBtnLogin_Click" />            

后台判断

    protected void imgBtnLogin_Click(object sender, ImageClickEventArgs e)

    {

        HttpCookie cookie = Request.Cookies["CheckCode"];

        if (cookie.Value == this.Validator.Text.Trim())

        {

            //。。。

        }

        else

        {

            Response.Write("<script>alert('验证码输入错误，请重新输入！');Location='ChineseCodeValidator.aspx'</script>");

            return;

        }

    }

以上验证码生成四位，请各位根据 情况做适当修改。

现在总结了生成纯数字、数字字母混合、纯汉字的验证码技术。希望对各位有所帮助。。