In VLF-WIN code you can directly access the VL trees (class #PRIM_TRVW) that are used to visualize the instance list content.
There may be two trees – the primary tree and possibly a secondary tree when side-by-side or over-under displays are used.
Once you have a reference to the tree you can access the items with in the tree and the columns within the items.
The properties #avListManager.avPrimaryTree and #avListManager.avSecondaryTree yield references to the primary and secondary VL trees used to visualize an instance list.
Some significant usage points:
Get the number of entries in primary visualization tree
#Std_text := #AVLISTMANAGER.avPrimaryTree.Entries.AsString
Use MESSAGE_BOX_SHOW With_Args(ok ok info *COMPONENT ('Tree has ' + #Std_text + ' entries'))
Change the icon associated with every entry at level 1 in a tree
For Each(#TreeItem) In(#avListManager.avPrimaryTree.Items)
#TreeItem.Image <= #vf_ic004
Note: This example is iterating over the tree so it is working in the visual order of the currently displayed tree - not necessarily the order of the instance list entries.
Make sure the first entry in the tree is visible
#avListManager.avPrimaryTree.Items<1>.EnsureVisible := True
Note: This example does not cater for an empty tree.