fdf_get_file (PHP 4, PHP 5 < 5.3.0, PECL fdf SVN)fdf_get_file — Get the value of the /F key 说明 fdf_get_file(resource $fdf_document): string Gets the value of the /F key. 参数 fdf_document The FDF document handle, returned by fdf_create(), fdf_open() or fdf_open_string(). 返回值 Returns the key value, as a string. 参见 fdf_set_file() - Set PDF document to display FDF data in