通过PHP下载的应用程序文件无法运行怎么处理

		$fs = fopen($_finame,'r');
		$_fisize = filesize($_finame);
		Header("Content-type: application/octet-stream");
		Header("Accept-Ranges: bytes");
		Header("Accept-Length: ".$_fisize);
		Header("Content-Disposition: attachment; filename=".basename($_finame));
		$buffer = 512;
		while(!feof($fs)){
			$_fidata = fread($fs,$buffer);
			echo $_fidata;
		}
		fclose($fs);