从子类调用视图

Question

I have an iPhone app primarily made of two views, let's call them fullScreen and cardViews (the cardViews are presented as subViews of the full screen views). I've handled all of the animations in presenting the card Views by having a masterCardViewClass and a masterFullScreenViewClass . All specific cardViews are subclasses of the masterCardView, all specific fullScreenViews are subclasses of the masterFullScreenView.

I present a cardView with a method from the masterFullScreenViewClass . I dismiss the cardView with a delegate method from the masterCardView. However, I'm having a problem calling a method to present a cardView from another cardView. All cardView presenting methods are contained in the masterFullScreenViewController class.

How do I access these methods without copying a pasting them locally where I need them.

Answer 1

One way of doing it is by using protocols.

In a nutshell, your masterCardView class would implement a protocol method that presents a cardView (for the sake of simplicity, let's say that you invoke cardViews with a certain index):

masterCardView.h:

@protocol CardPresenterDelegate <NSObject>

- (void)presentCardViewWithIndex:(int)index;

@end

@interface MasterCardView:UIViewController <CardPresenterDelegate>
...

masterCardView.m:

- (void)presentCardViewWithIndex:(int)index
{
// Code for presenting a cardView
}

You would also need to create a delegate (weak) property in your cardView:

cardView.h

@property (weak) id<CardPresenterDelegate> cardPresenterDelegate;

And then by accessing that property in your cardView, you can tell the masterCardView to do something for you:

cardView.m

[self.cardPresenterDelegate presentCardViewWithIndex:5];

Oh, and, don't forget to set the delegate property on your cardViews when creating them in your masterCardView:

back in masterCardView.m:

cardView.cardPresenterDelegate = self;