从自定义UITableView获取DidEndScroll委托方法

Question

I am using the a custom UITableView called UIBubbleTableView.

In my View Controller that I am setting up the UIBubbleTableView everything works fine. I however am trying to implement lazy loading so I need to know what cells are visible. Unfortunately I can't access the UITableView delegate method of the UIBubbleTableView. I tried looking around StackOverflow and I read chaining delegates is a good idea. So I am creating a delegate in UIBubbleTableView.h

However when I put in @property (nonatomic, weak) id<UIBubbleTableViewDelegate> delegate;

I got Property type 'id<UIBubbleTableViewDelegate>' is incompatible with type 'id<UITableViewDelegate>' inherited from 'UITableView'

Is chaining delegates really the best method or is there another solution. I thought about using NSNotification, but I am guessing that has performance implications.

Thanks!

Answer 1

I can't access the UITableView delegate method of the UIBubbleTableView

Why on earth not? Of course you can! After all, UITableView's delegate gets scrollViewDidScroll not because it is a UITableView but because it is a UIScrollView. Well, so then does UIBubbleTableView. It is both a UITableView and a UIScrollView. That is what inheritance means.

You do not need to declare a @property . UIBubbleTableView already has a delegate property, inherited from its superclass, UITableView. Again, that is what inheritance means. Just set the delegate the way you would for any table view, either in code or through an outlet. There is no need to declare anything, no need to chain anything. The table view delegate is the UIBubbleTableView delegate.

If you need another delegate (one for some UIBubbleTableView delegate protocol methods and another for the UITableView delegate protocol methods) then you will have to give that property a different name, won't you?