Hello dz_uc,

On the following link http://yinyangme.com/blog/post/The-simplest-way-to-detect-DoubleClick-in-Silverlight.aspx you can find a way to implement logic for detecting double click of the mouse. I used it in my sample in order to make the current node to be expanded or collapsed when double clicking. I am attaching to MouseLeftButtonDown to detect double click and to ActiveNodeChanging to find the current node. You can review the sample and see if it is suitable for your scenario! Thank you in advance!

Regards,

Nikola.