Instead of UICollectionView a black screen is displayed

Question

I'm trying to reimplement the infinitive scrolling UICollectionView seen here. Things that were missing for me:

ViewController.h:

@interface ViewController : UIViewController<UICollectionViewDataSource, UICollectionViewDelegate>

@end

DataCell.h:

@interface DataCell : UICollectionViewCell
@property (nonatomic, strong) UILabel *label;
@end

DataCell.m:

#import "DataCell.h"

@implementation DataCell

-(instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if(self){
        self.label = [[UILabel alloc] initWithFrame:self.bounds];
        self.autoresizesSubviews = YES;
        self.label.autoresizingMask = (UIViewAutoresizingFlexibleWidth |
                                       UIViewAutoresizingFlexibleHeight);
        self.label.textAlignment = NSTextAlignmentCenter;
        self.label.adjustsFontSizeToFitWidth = YES;

        [self addSubview:self.label];
    }

    return self;
}

@end

CustomCollectionView.h:

@interface CustomCollectionView : UICollectionView

@end

For the whole project I used a storyboard and a normal UIViewController. On this view controller I added a UICollectionView in Interface Builder. I connected the outlet from the collection view with my view controller and set up the datasource and delegate methods again to my view controller. I also set the custom class of the UICollectionViewCell and the reuse identifier in Interface Builder.

So everything should work but I only get a black screen. What I'm missing? You can download the whole project here.

score 25 · Accepted Answer · answered Mar 31 '15 at 12:07

25

You are configuring correctly the CollectionView, just that you forgot the color of the label :)

    [self.label setTextColor:[UIColor whiteColor]];

enter image description here

Hope it helps!

answered Mar 31 '15 at 12:07

Javier Flores Font

1,995
13
13

score 5 · Answer 2 · answered Jul 27 '16 at 11:34

5

You need to manually set the background color of the collection view in the storyboard.

By default it is black (although not showing that in the storyboard editor)

answered Jul 27 '16 at 11:34

SoliQuiD

1,717
18
26

if you want the background to be clear, you have to use `collectionView.backgroundColor = [UIColor clearColor];` and `collectionView.backgroundView = [[UIView alloc] initWithFrame:CGRectZero];` – Multinerd Dec 01 '16 at 21:11

score 4 · Answer 3 · answered Feb 24 '16 at 04:47

I had the same issue. The black screen seems to be an indicator of no data available with collection view to display. Try changing the background color of the collection view, if that changed color got to display, your collection view is working. And then add some imageview to the collection view with tag (Ex. give a value 100 with the tag value for the image view) and with the cellforItemAtIndexPath set the images to the image view. (You can do this with custom cell. But for now, to get the collection view work, the assignment with tag for the imageview suits better)

UIImageView * ImageView = (UIImageView *)[cell viewWithTag:100];
ImageView.image = [UIImage imageNamed:[images objectAtIndex:indexPath.row]];

score 2 · Answer 4 · answered Oct 14 '17 at 17:55

2

it happened to me that both the collectionView and the collection view cell had transparent backgrounds

answered Oct 14 '17 at 17:55

Dan Precup

75
1
4

score 1 · Answer 5 · answered Jul 28 '16 at 15:58

1

In Swift,

self.label.textColor = UIColor.whiteColor()

answered Jul 28 '16 at 15:58

Ghulam Rasool

3,421
2
21
36

score 1 · Answer 6 · edited Oct 13 '16 at 08:08

1

[self.collectionView registerNib:[UINib nibWithNibName:@"ProductCollectionViewCell" bundle:nil] forCellWithReuseIdentifier:@"ProductCollectionViewCell"];

self.collectionView.backgroundColor = [UIColor clearColor];

edited Oct 13 '16 at 08:08

testing

17,950
38
208
373

answered Oct 13 '16 at 05:45

Mr.Javed Multani

9,803
2
42
45

Instead of UICollectionView a black screen is displayed

6 Answers6

Linked