/// <summary>
        /// 保存文件对话框
        /// </summary>
        /// <param name="FilePath">要保存的文件全路径</param>
        public static void FileSaveDialogBox(string FilePath)
        {
            string filename = System.IO.Path.GetFileName(FilePath);
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ContentType = "application/octet-stream";
            //这里的filename可以输出时自定义,不一定用原来的.      
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "p_w_upload;filename=" + filename);
            HttpContext.Current.Response.TransmitFile(FilePath);
            HttpContext.Current.Response.Flush();
            HttpContext.Current.Response.Close();
        }