问题
What are my options for viewing hierarchies in iOS? In OSX I have the option of using NSOutlineView. Ideally I should be able to support at least 3 levels.
回答1:
Not much. Table views support sections and rows, which gives you 2 levels.
You could use a UICollectionView and roll your own hierarchy of data, but I don't think there is an equivalent to NSOutlineView in iOS. The UI Elements are designed for the small screen on a phone, where you don't really have enough space to present multiple levels of data. Apple added a few extra controls like a split view controller for iPad, but not really an outline viewer.
The norm on iOS is to use multiple levels of master/detail views. You drill down from the top level item by item until you get to the detail you're looking for.
来源：https://stackoverflow.com/questions/18925201/viewing-hierarchy-in-ios