下传上载附件的服务 中文乱码有关问题 在线求解

string fileName = HttpUtility.UrlDecode(context.Request.QueryString["FileName"], Encoding.GetEncoding("UTF-8"));
            //context.Response.ContentEncoding = System.Text.Encoding.Unicode;
            string relativefilePath = context.Request.QueryString["FilePath"];　//文件相对路径
            string filePath = context.Server.MapPath(relativefilePath);
            string strType = context.Request.QueryString["ViewType"];

                FileInfo fileInfo = new FileInfo(filePath);
                if (fileInfo.Exists)
                {
                    context.Response.Clear();
                    context.Response.ClearHeaders();
                    context.Response.Buffer = true;
                    context.Response.Charset = "GB2312";
                    context.Response.ContentType = "application/octet-stream";
                    context.Response.ContentEncoding = System.Text.Encoding.UTF8;　
                    //弹出下载框
                    if (strType != "View")
                    {
                        context.Response.AppendHeader("Content-disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
                    }
                    else
                    {
                        //直接打开
                        context.Response.AppendHeader("Content-disposition", "inline;filename=" + System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
                    }
                    context.Response.AddHeader("Content-Length", fileInfo.Length.ToString());
                    context.Response.WriteFile(filePath);
                    context.Response.Flush();
                    context.Response.End();
                }

            }

<globalization requestEncoding="gb2312"  responseEncoding="utf-8" fileEncoding="utf-8"/>