Owen Thanks for your advice, but I've already tried this and this method doesn't completely solve my problem.
If I remove the selection and switch to the parent element, then in my case the node will collapse.
Of course, I can disable collapsing for a while, but the visual effect of the last selected item is lost, which is not exactly good for the user.
Owen, could you add an additional event handler for the tree, if possible, to re-select an element similar to SelChanged, for example "Selection"?
Sorry Owen that I will ask one question off-topic. My application works in AutoCAD, Bricscad and ZwCAD, but now the number of users who ask for nanoCAD support is growing. Is it possible to add nanoCAD support to OpenDCL and how long can it take?
Owen I would like to thank you very much for your hard work in the development of Opencl and hope that you will not lose the desire to develop this product in the future. Thank you so much, you are the best!!!