Tree View Item - HasChildren Property
Controls the appearance of the expand and collapse image for the item
Member of Tree View Item (PRIM_TVIT)
Data Type - Enumeration
Details
The HasChildren property is used to control the appearance of the expand/collapse image for an item.
By default the control will show the correct icon for an item. If there are no child items, no expand image will be shown.
When building trees on demand it is necessary to show the expand item even though there are no child items yet. This means that the item can expand, and the HasChildren can be tested to see whether there is a need to load the branch.
Allowed Values
Enum Value |
Description |
No |
Hide the expand/collapse image. The item cannot be expanded. |
Unknown |
Show the expand/collapse image. The item can be expanded. |
Yes |
Show the expand/collapse image. The item can be expanded. |
Example
In this example of how you might handle dynamically loading a tree, if there are already child items for an expanding item, they are deleted and the branch reloaded.
Evtroutine Handling(#List.ItemExpanding)
Case (#List.CurrentItem.HasChildren)
When (= Unknown)
#Com_owner.LoadBranch
When (= Yes)
#List.CurrentItem.DeleteAll
#Com_owner.LoadBranch
Endcase
Endroutine