IOS : UICollectionView inside UIScrollView index not incremented

Question

Hello people of stackoverflow,

Currently working on an App where I have a user profile that looks like this

https://i.stack.imgur.com/l9LBX.jpg (sorry I dont have enough reputation to post the image)

Header View is a picture of the user. Tab View is 2 tabs, one with a collectionview, the other with a tableview.

All those views are nested inside a scrollView

My problem is that when I scroll that view (collection view height set programmaticaly depending on number of elements), the collection view's index does not increment. Only the 6 first items are loaded in in the visible cells index of the collection view.

I need to segue from the collectionview's items to the item's detail view.

How can I use the scrollView delegate to know where my collection view is at.

I've looked at those threads : iOS 7 Collection View inside Scroll View How to implement non-scrollable UICollectionView inside UIScrollView?

But none gave me the answer I was looking for.

I also tried looking at scrollViewDidEndDecelerating and setting my collection view scroll offset according to the scroll view offset, but I could not make it work.

Any advices?

Thanks

EDIT :

Hello and thanks for your answer,

To answer your question, I can scroll my collectionview, since it is inside a scroll view, I set my collectionview height during viewdidload (based on number of elements)

my problem is, I can click on the first 6 items , and display details (via a segue) but after that, selection is not recognized as the index is not refreshed for my collection view. I can scroll all the way to the bottom of my collection view (I scroll via the scrollView).

My collectionView has user interaction enabled checked, as I said, I can select the first 6 items, and then selection is not recognized.

I understand the UICollectionViewFlowLayout issue, but where do I write this line ? in the viewDidLoad? or in delegate funcs of CollectionView ?

If you need more information, I can copy some code or show you the layout of the view in storyboard

Thanks in advance.

EDIT 2 :

images , storyboard : layout of my view

http://i.gyazo.com/c491786507db2effc702d910020515a2.png

code, here are the datasource funcs of the collectionView

http://gyazo.com/3730caeb2b2a40fef9efec559171744f

delegate func of the collection view

http://i.gyazo.com/81fc9443b4367ecbd304e608ab0cc864.png

EDIT3:

Okay so basically this is what I want to reproduce,

tab view in the middle with multiples tabs with collection view, all this scrollable. What I cant understand, is if I set my topView as the header of the CollectionView, I can't switch tabs like I want since its inside the header.

ViewController with TalbeView and CollectionView tabs like Google+ in IOS

Answer 1

Hi First of all I need more detail about your question but I am assuming that you want your UICollectionView scrollable and actually its not scrolling.

So could you check following points :-

1. UserEnableInteraction for collection view should be enabled.

2. And also check what is the value you gave for UICollectionViewFlowLayout because just consider if You have total 5 elements to show and your UICollectionViewFlowLayout size is like it can show all five items in visible cell index then it doesn't scroll so you need to increase the size of UICollectionViewFlowLayout to make it scroll. e.g

UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];

[flowLayout setItemSize:CGSizeMake(148, 148)];

3. And if you want then you can get the help from UIScrollViewDelegate method like

   - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
   {
   if (!decelerate)
   {
       // do your job
   }
   }
   

Answer 2

set delegates and Datasource in .h

#import <UIKit/UIKit.h>
 @interface ViewController : UIViewController<UITableViewDataSource , UITableViewDelegate ,         
  UIScrollViewDelegate , UICollectionViewDataSource , UICollectionViewDelegateFlowLayout>

You can do that .m in ViewDidLoad:-

    UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
    UICollectionView *collectionView =[[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:layout ];
    collectionView.frame = CGRectMake(5, 61, 365, 678);
    collectionView.delegate = self;
    collectionView.dataSource = self;
    [collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentifier"];
    [self.view addSubview:collectionView];

And then Call her delegates method :-

 - (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return [arrImages count];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath];
    [self createCell:cell forTableview:collectionView];

    [self fillCell:cell cellForRowAtIndex:indexPath];
     return cell;
}

//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
//{
//    return CGSizeMake(50, 50);
//}