asp.net 文件下载 文件名称乱码 处理~~

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.IO;

using ElementLibrary.BLL; using ElementLibrary.MODEL; using System.Text; /*  * LiuH  * Descr:下载处理DownLoadFile.ashx  * Addtime：2014/8/26  * LastModifyTime:2014/8/27  */ namespace ElementLibrary.Web.Action {     /// <summary>     ///DownLoadFile 的摘要描述     /// </summary>     public class DownLoadFile : IHttpHandler     {         ElementDetailBLL elementDetailBLL = new ElementDetailBLL();         public void ProcessRequest(HttpContext context)         {             string strFunId = context.Request.QueryString["id"].ToString();//获取方法id(元件ID)             MODEL.ElementDetailInfo elementDetailInfo = elementDetailBLL.GetAllContent(strFunId);//客户端保存的文件名             string fileName = elementDetailInfo.FileName;             string strFilePath = elementDetailInfo.FilePath;             string filePath = context.Server.MapPath(strFilePath);//路径             FileInfo fileInfo = new FileInfo(filePath);             context.Response.Clear();             context.Response.ClearContent();             context.Response.ClearHeaders();            //解决文件名乱码（LiuH AddTime:2014/8/28）             if (context.Request.UserAgent.Contains("MSIE") || context.Request.UserAgent.Contains("msie"))             {                 // 如果客户端使用 Microsoft Internet Explorer，则需要编码                  fileName = ToHexString(fileName);             }             context.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);             context.Response.AddHeader("Content-Length", fileInfo.Length.ToString());             context.Response.AddHeader("Content-Transfer-Encoding", "binary");             context.Response.ContentType = "application/octet-stream";             context.Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8");             context.Response.WriteFile(fileInfo.FullName);             context.Response.Flush();             //fileInfo.Delete();             context.Response.End();         }

        /// <summary>         /// 为字符串中的非英文字符编码         /// </summary>         /// <param name="s"></param>         /// <returns></returns>         public static string ToHexString(string s)         {             char[] chars = s.ToCharArray();             StringBuilder builder = new StringBuilder();             for (int index = 0; index < chars.Length; index++)             {                 bool needToEncode = NeedToEncode(chars[index]);                 if (needToEncode)                 {                     string encodedString = ToHexString(chars[index]);                     builder.Append(encodedString);                 }                 else                 {                     builder.Append(chars[index]);                 }             }

            return builder.ToString();         }

        /// <summary>         ///指定 一个字符是否应该被编码         /// </summary>         /// <param name="chr"></param>         /// <returns></returns>         private static bool NeedToEncode(char chr)         {             string reservedChars = "$-_.+!*'(),@=&";

            if (chr > 127)                 return true;             if (char.IsLetterOrDigit(chr) || reservedChars.IndexOf(chr) >= 0)                 return false;

            return true;         }

        /// <summary>         /// 为非英文字符串编码         /// </summary>         /// <param name="chr"></param>         /// <returns></returns>         private static string ToHexString(char chr)         {             UTF8Encoding utf8 = new UTF8Encoding();             byte[] encodedBytes = utf8.GetBytes(chr.ToString());             StringBuilder builder = new StringBuilder();             for (int index = 0; index < encodedBytes.Length; index++)             {                 builder.AppendFormat("%{0}", Convert.ToString(encodedBytes[index], 16));             }             return builder.ToString();         }

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