Hi Grigoriy,
Thank you for your question.
You can do this by creating a class which inherits from RadTreeView and a class which inherits from RadTreeViewTextEditor. In the new text editor you can override the OnKeyDown method and check for the escape key.
Please see the sample code below, it demonstrates how this can be done.
Please note that currently RadTreeView does not fire KeyPress or KeyDown because all input is redirected to the editor of the node you are editing.
Do not hesitate to write again if you need further assistance.
Sincerely yours,
Victor
the Telerik team