xcode - UICollectionView doesn't contain UICollectionViewCell in IB

Question

I'm trying to add a UICollectionView to a .nib file in IB. I've worked through a few tutorials and had no problems.

In my existing app, when I drag a collection view into a view in IB and then expand the object, the CollectionView Flow Layout is there , but there is no collection view cell. I also cannot drag and drop a cell into the collection view. Also the collection view is displayed differently, showing an image of a grid of cells instead of the normal white box.

I've tried creating a new view controller with nib, and have the same results when adding a collectionView.

This app WAS targeting iOS 4.2, but I've changed the deployment target to iOS 6.

In any newly created projects I don't get this behavior.

Answer 1

I can't tell you why it does not work, but for me the subclass approach from this blog post solved the problem:

http://www.adoptioncurve.net/archives/2012/09/a-simple-uicollectionview-tutorial.php

here is a short summary:

• create a new class MyViewCell which extends UICollectionViewCell and create properties, actions, outlets and methods as needed.

@interface MyViewCell : UICollectionViewCell

• create a View (xib file) with a Collection View Cell as its root object (and delete the object which is created by default).
• in the attributes set the custom class of this Collection View Cell to your extended class MyViewCell (instead of the default UICollectionViewCell).
• in the attributes under Collection Reusable View define an Identifier, e.g. myCell, you will need this later to register your call.

• go back to your custom class and modify the inithWithFrame method to load and use your created view.

  - (id)initWithFrame:(CGRect)frame 
  { 
     self = [super initWithFrame:frame]; 
     if (self) 
     { 
       // Initialization code 
       NSArray *arrayOfViews = [[NSBundle mainBundle] loadNibNamed:@"CVCell" owner:self options:nil];
  
       if ([arrayOfViews count] < 1) { return nil; }
  
       if (![[arrayOfViews objectAtIndex:0] isKindOfClass:[UICollectionViewCell class]]) { return nil; }
  
       self = [arrayOfViews objectAtIndex:0];
     }
     return self;
  }
  

• then you can register this class to be used by the collectionView with

[self.collectionView registerClass:[MyViewCell class] forCellWithReuseIdentifier:@"myCell"];