Get the number of children attached to a layer display order node.
getLayerOrderNumChildren([in] LONG orderHandle, [out, retval] int *numChildren)
PDF files with layers contain a tree structure that specifies the way layers are intended to be displayed to the user. Each node in the tree has either a name or a layer. Named nodes are used to provide a hierarchical structure for the layers, with labels to help the user. Each node also optionally has a list of child nodes.

This function returns the number of children that the specified layer order tree node has.

scanLayerOrder(viewer.getLayerOrderRoot()) ... Sub scanLayerOrder(order As Long) Dim name As String Dim layer As Long If viewer.getLayerOrderIsName(order) Then ' this node has a name name = viewer.getLayerOrderName(order) ... Else ' this node has a layer layer = viewer.getLayerOrderLayer(order) ... End If nChildren = viewer.getLayerOrderNumChildren(order) For i = 0 To nChildren - 1 scanLayerOrder(viewer.getLayerOrderChild(order, i)) Next i End Sub