OPMS/03-程式設計階段/TmpWeb/OT.Web/GetImg.ashx.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
using System.Linq;
using System.Web;
using DBUtility;
using OT_Web.Ap_Code;
using OT.Web.Ap_Code;

namespace OT_Web
{

    /// <summary>
    ///Common 的摘要描述
    /// </summary>
    public class GetImg : IHttpHandler
    {
        //Add by Ethan, 2014/10/15 Start. 處理圖片路徑變更
        private static string gstrFileWebRoot = "";
        static GetImg()
        {
            gstrFileWebRoot = (DbHelperSQL.GetSingle(" SELECT SettingValue FROM dbo.OTB_SYS_SystemSetting WHERE SettingItem='DmImgWebPath' ") ?? "").ToString();
        }
        //Add by Ethan, 2014/10/15 End. 處理圖片路徑變更

        /// <summary>
        /// 生成驗證碼字符串
        /// </summary>
        /// <param name="codeLen">驗證碼字符長度</param>
        /// <returns>返回驗證碼字符串</returns>
        private string MakeCode(int codeLen)
        {
            if (codeLen < 1)
            {
                return string.Empty;
            }

            int number;
            string checkCode = string.Empty;
            Random random = new Random();

            for (int index = 0; index < codeLen; index++)
            {
                number = random.Next();

                if (number % 2 == 0)
                {
                    checkCode += (char)('0' + (char)(number % 10));     //生成數字
                }
                else
                {
                    checkCode += (char)('A' + (char)(number % 26));     //生成字母
                }
            }

            return checkCode;
        }

        //      ///<summary>
        /// 獲取驗證碼圖片流
        /// </summary>
        /// <param name="checkCode">驗證碼字符串</param>
        /// <returns>返回驗證碼圖片流</returns>
        private MemoryStream CreateCodeImg(string checkCode)
        {
            if (string.IsNullOrEmpty(checkCode))
            {
                return null;
            }

            Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);

            Graphics graphic = Graphics.FromImage(image);

            try
            {
                Random random = new Random();

                graphic.Clear(Color.White);

                int x1 = 0, y1 = 0, x2 = 0, y2 = 0;

                for (int index = 0; index < 25; index++)
                {
                    x1 = random.Next(image.Width);
                    x2 = random.Next(image.Width);
                    y1 = random.Next(image.Height);
                    y2 = random.Next(image.Height);

                    graphic.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                }

                Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Red, Color.DarkRed, 1.2f, true);
                graphic.DrawString(checkCode, font, brush, 2, 2);

                int x = 0;
                int y = 0;

                //畫圖片的前景噪音點
                for (int i = 0; i < 100; i++)
                {
                    x = random.Next(image.Width);
                    y = random.Next(image.Height);

                    image.SetPixel(x, y, Color.FromArgb(random.Next()));
                }

                //畫圖片的邊框線
                graphic.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

                //將圖片驗證碼保存為流Stream返回
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                return ms;
            }
            finally
            {
                graphic.Dispose();
                image.Dispose();
            }
        }

        public void ProcessRequest(HttpContext context)
        {
            try
            {
                string strFilePath = SecurityUtil.DESDecrypt(context.Request["F"].Replace(" ", "+"), "1234567890123456", "1234567890123456");
                //Add by Ethan, 2014/10/15 Start. 處理圖片路徑變更
                if (strFilePath != null && !File.Exists(strFilePath))
                {
                    strFilePath = gstrFileWebRoot.Trim('/') + "/" + strFilePath.Replace("\\", "/").Substring(strFilePath.ToLower().IndexOf("dmimg"));
                }
                //Add by Ethan, 2014/10/15 End. 處理圖片路徑變更
                string code = "出現錯誤";//MakeCode(5);
                MemoryStream ms = CreateCodeImg(code);
                if (!string.IsNullOrEmpty(strFilePath))
                {
                    ms = new MemoryStream(File.ReadAllBytes(strFilePath));
                }
                if (null != ms)
                {
                    context.Response.ClearContent();
                    context.Response.ContentType = "image/Gif";
                    context.Response.BinaryWrite(ms.ToArray());
                }
            }
            catch (Exception)
            {

            }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}