public static bool ValidateFlash(string fileName)

        {

            byte[] header = new byte[8];

            FileStream fs = new FileStream(fileName, FileMode.Open);

            try

            {

                fs.Read(header, 0, 8);

            }

            finally

            {

                fs.Close();

            }

            string ext = Path.GetExtension(fileName);//文件扩展名

            string sHeader = Encoding.Default.GetString(header);

            sHeader = sHeader.Substring(0, 3);

            //文件头三个字节"FWS(无压缩),CWS(标准ZLIB已压缩)"

            return (ext.ToUpper() == ".SWF") && ((sHeader == "FWS") || (sHeader == "CWS"));

        }