public class FileUtils    {        /// 
        /// 文件下载        /// 
        /// 页面参数        /// 文件源路径        /// 文件命名        public static void FileDownload(System.Web.UI.Page page, string filePath, string saveFileName)        {            try            {                if (!string.IsNullOrEmpty(filePath))                {                    string fileExtension = filePath.Substring(filePath.LastIndexOf('.'));//后缀                    //saveFileName = filePath.Substring(filePath.LastIndexOf(@"\"));//文件名                    page.Response.Clear();                    page.Response.AddHeader("Content-Disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(System.Text.Encoding.UTF8.GetBytes(saveFileName)));                    page.Response.Charset = "utf-8";                    page.Response.ContentEncoding = System.Text.Encoding.Default;                    page.Response.WriteFile(filePath);                    //page.Response.Flush();                    page.Response.End();                   //HttpContext.Current.ApplicationInstance.CompleteRequest();                }            }            catch {   }        }        /// 
        /// 文件导出        /// 
        /// 对象页面        /// 文件保存服务器路径        /// 数据源        /// 导出后的文件名称        public static void ExportFile(System.Web.UI.Page page, string filePath, DataTable dt, string exportFileName)        {            try            {                if (File.Exists(filePath))                {                    File.Delete(filePath);                }                StreamWriter sw = new StreamWriter(new FileStream(filePath, FileMode.CreateNew), System.Text.Encoding.GetEncoding("GB2312"));                sw.Write(exportFileName);                sw.WriteLine();                int i = 0;                for (i = 0; i <= dt.Columns.Count - 1; i++)                {                    sw.Write(dt.Columns[i].ColumnName);                    sw.Write('\t');                }                sw.WriteLine();                foreach (DataRow dr in dt.Rows)                {                    for (i = 0; i <= dt.Columns.Count - 1; i++)                    {                        sw.Write(dr[i].ToString());                        sw.Write('\t');                    }                    sw.WriteLine();                }                sw.Close();                FileDownload(page, filePath, exportFileName);            }            catch { }        }    }