(PECL pdflib >= 2.0.0)
PDF_set_layer_dependency — Define relationships among layers
$pdfdoc
, string $type
, string $optlist
) : bool
Defines hierarchical and group relationships among layers. �ɹ�ʱ���� TRUE�� ������ʧ��ʱ���� FALSE��
This function requires PDF 1.5.