声明：
DATA: l_layout_node TYPE lvc_s_layn,
p_node_image type TV_IMAGE.
p_node_image = '@AV@'.
l_layout_node-isfolder = 'X'. "add a folder, NOT a leaf
l_layout_node-n_image = p_node_image. "Display an icon
DATA p_node_text TYPE lvc_value.
在添加树状数据中，设置
LOOP AT it_order.
l_node_text = it_order-carrid.
CALL METHOD g_alv_tree->add_node
EXPORTING
i_relat_node_key = l_top_key
i_relationship = cl_gui_column_tree=>relat_last_child
i_node_text = l_node_text
is_node_layout = l_layout_node "为显示的字段设置图片
IMPORTING
e_new_node_key = l_first_key.
it_order-l_key = l_first_key.
MODIFY it_order.
CLEAR it_order.
ENDLOOP.