使用js+一般处理程序在静态页面处理带图片的验证码

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

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;

//引用的命名空间

using System.Drawing;

using System.Drawing.Drawing2D; 



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

{

    /// <summary>

    /// 页面加载

    /// </summary>

    /// <param name="sender"></param>

    /// <param name="e"></param>

    protected void Page_Load(object sender, EventArgs e)

    {

        CreateCheckCodeImage(GetExpressions());//页面加载时调用产生算数运算式的方法

    }

    /// <summary>

    /// 产生算术运算式

    /// </summary>

    private string GetExpressions()

    {

        Random rd = new Random(); //创建随机数对象       

        int Results = 0;

        int Num1 = rd.Next(10); ;

        int Num2 = rd.Next(10); ;

        string Expressions = "";

        int F = (rd.Next(3) + 1);

        switch (F)

        {

            case 1:

                Results = Num1 + Num2;

                Expressions = Num1 + " 加上 " + Num2;// +" 结果是" +Results;

                break;

            case 2:

                Results = Num1 - Num2;

                Expressions = Num1 + " 减去 " + Num2;

                break;

            case 3:

                Results = Num1 * Num2;

                Expressions = Num1 + " 乘以 " + Num2;

                break;

            case 4:

                if (Num2 > 0)

                {

                    Results = Convert.ToInt16(Num1 / Num2);

                    Expressions = Num1 + " 整除 " + Num2;

                }

                else

                {

                    Results = Num1;

                    Expressions = Num1 + " 整除 1";// + Results;

                }

                break;

        }

        //验证码值存放到Session中用来比较

        Session["Code"] = Results.ToString();

        return Expressions;

    }

    /// <summary>

    /// 生成图片（增加背景噪音线、前景噪音点）

    /// </summary>

    /// <param name="checkCode">随机出字符串</param>

    private void CreateCheckCodeImage(string checkCode)

    {

        if (checkCode.Trim() == "" || checkCode == null)

            return;

        System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)(checkCode.Length * 14), 26);

        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);

            //画图片的背景噪音线

            int i;

            for (i = 0; i < 25; 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);

            }

            //定义一个含10种字体的数组

            String[] fontFamily = { "Arial", "Verdana", "Comic Sans MS", "Impact", "Haettenschweiler", "幼圆", "黑体", "隶书", "宋体", "楷体_GB2312" };

            FontStyle[] fontStyle = { FontStyle.Bold, FontStyle.Italic, FontStyle.Regular, FontStyle.Strikeout, FontStyle.Underline };

            Font font = new System.Drawing.Font(fontFamily[random.Next(9)], 12, fontStyle[random.Next(5)]);

            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(checkCode, font, brush, 2, 2);



            //画图片的前景噪音点

            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

        {

            g.Dispose();

            image.Dispose();

        }

    }

}