Although, some devlopers said the "fat finger" problem may lead the android platform hasn't implementation the treeview. Some apps still need this feature, for instance a tree directory. And I have noticed that some guys asked some for this. So here, I just share some information for this feature.
You can directly go to below link. Because this link from China, if you have some questions, please feel free to answer any questions. They can use english to do the response:)