Gregory,

this is from my far remembrance. ::)

The days I've started treeview was the days I've started VFP, so it's all old and forgotten.
But I can remember problems with non closing forms (or environments what is mostly the sign of a form not closed to dead). The form was gone, all 'known' references where gone, but the DS was still there.

In these days I've have done a lot with the child and sibbling properties of nodes. (I.e. iterating through the nodes and the like). The problem was bound to those calls. I traced it down to see that the problem occurs after those calls. Now I use I mirroed structure for the nodes to get the information I need and the problem is gone.

I know this all is not very sophisticated, but again, this is from the times I know not much about VFP - and it's very old. I hope it will give you an idea to search.

I use treeviews a lot and can tell you that treview or treelist will not create a dataenvironment.

What you can do is to test if the DS left is the same as the DS of your form.
Try to run

?SET("Datasession")

in your form and in the unknown DS.
If the number is the same, then the form is not closed.

If not...

Try to trace where the DS is created. I guess ASESSIONS() is not available in VFP6SP5, so you need to check the datasession window.

HTH

Agnes
>Hi all,
>
>I've got a Form with a (subclassed) container ( Treeview control and ImageList control ).
>The Form has a private datasession. Closing the form leaves an unknown datasession behind. The form closes normally.
>
>Except for

this.Treeview.ImageList = this.ImageList

in the init() of the container, there are no object references being kept.
>
>Any solution to get rid of the unknown datasession ? (vfp6sp5)
>
>Leaving the ImageList out does not help either
>
>Thanks,