[SOLVED] Treeview, possible to late set Node.HasChildren (plus sign)?

[d7_2_laz]

The outcome is: the pinciple is nicely applicable to apps too that don't use the ShellControls itself: it works very fine and fast!
Tremendous speedup .. perfectly solved!

[wp]

Committed to trunk and requested back-porting to v2.2RC2.

The largest part of the slow-down when a heavily populated node is opened a second time is due to a missing BeginUpdate/EndUpdate pair around Node.DeleteChildren in the ShellTreeView's CanExpand method (about 20 s for c:\Windows\WinSxS) - but this was already included in the pre-version that you used. With BeginUpdate/EndUpdate the delay shortens to about 1 second. I checked the involved procedures and found nothing suspicious. The problem seems to be that all subnodes have to be iterated when their parent node is closed.

[d7_2_laz]

Had guessed such a direction, as after transfer of the change to my app, here the effect did _not_ occur.
I had already noticed this difference in CanExpand, but had not been sure if it was directly related to your recent change / this specific topic.

Btw, it is good to see that the fix from the thread "Trouble with CustomTreeView (OnExpand)" (SIGSEGV at CanExpand when inside Begin-/End-Update) indeed is part of 2.2 - the problem did not reoccur here.

A lot of thanks for having involved so deeply! Great experience.