How can do tree structure for file or directory?

Answer 1

Thank you

Answer 2

Have a look a this link.
Use your on laptop since the playground does not support file-operations.

https://www.c-sharpcorner.com/article/display-sub-directories-and-files-in-treeview/

http://csharphelper.com/blog/2017/11/initialize-a-treeview-control-to-display-a-directory-hierarchy-in-c/

https://www.dotnetperls.com/recursive-file-list