If you want to disable expanding/collapsing of the treeview item on double click you can use the IsExpandOnDblClickEnabled
property of the treeview:
As for the events - if you want to manipulate the expanding and collapsing of treeview items you can use Expand\Collapse Events
of the treeview.
I hope this information will help you and don't hesitate to write back if you have more questions.
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