umg animation c++

dear all
some widget in my umg need some simly animation like sliding, and such widgets will also be created and destroyed dynamically… so i think the umg animation system wont be suitable…
i try to use timeline component in my customized userwidget, but also failed… pls see my question in answer hub…
https://answers.unrealengine.com/que…-run-once.html

anybody has some suggestion?? thanks in advance!!