获取UIView的容器/ UIViewController

Question

So I have a UIViewController A which adds a UIView B as a subclass. The UIView B has a UITableView. I want the UITableView scrollView delegate to be in the UIViewController A. How do I do this? As of now the scrollViewDidScroll delegate is inside this UIView class. Is there a way so that the scrollViewDidScroll is inside viewController A and is called whenever the UITableView in the UIView is scrolled?

Answer 1

Make the tableView as a property accessible from the outside. Than you could set it up in your ViewController A like that:

// ClassB.h
@property (nonatomic, readonly) UITableView* tableView;

// In your UIViewControllerA.m
// in loadView: or anywhere else
self.viewB.tableView.delegate = self;

So result is: your ViewController is the delegate.

Answer 2

The scroll view and the table view are the same object -- notice that UITableView is a subclass of UIScrollView. That object has only one delegate, not separate delegates for the table stuff and for the scroll stuff. Also notice that UITableViewDelegate adopts UIScrollViewDelegate. So, the object you set as the table's delegate will also get UIScrollViewDelegate messages.

Now, there's no reason that your table's delegate can't forward messages about scrolling to some other object. You'd have to set that up yourself, of course. So, when B gets a -scrollViewDidScroll: message, it might send an equivalent message to A, or whatever. I'd think twice before actually doing that, though... I'd try to have just one object (the view controller) be responsible for everything related to the table.