CODEWITHSUNDEEP
iosuicollectionviewuicollectionviewcell
phil swenson
phil swenson

Reputation: 8894

Trouble accessing Image from instance of UICollectionViewCell

I'm following this tutorial with some modifications for my project: http://www.appcoda.com/ios-programming-uicollectionview-tutorial/

I'm trying to get the instance of UIImageView that IB creates for me.

Here is a screenshot of my IB:

enter image description here

I have a custom class called FeedViewCell that is to contain an UIImageView. Here is the cellForItemAtIndexPath code:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    static NSString *identifier = @"Cell";

    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];

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

    return cell;
}

The problem is that UIImageView *imageView = (UIImageView *)[cell viewWithTag:100]; comes back as nil. Using the viewWIthTag method seems weird to me anyway, but in the debugger I see no sign that imageView is a subview of UICollectionViewCell. If you look at this debug screen, you can see that the cell doesn't appear to have any UIImageView subviews:

enter image description here

However I see 2 UIImageViews as subviews of the CollectionView.

So it seems to be that I'm doing something wrong in IB. This isn't surprising as I always seem to struggle with IB (looking at code at least I can see what's going on).

Thanks for any suggestions!

update: I gave up on using IB to hook in the ImageView and tried creating it in code as below: http://cl.ly/QFxs

The images don't display properly. If you look in the screenshot (debugger) though, you will see images and imageViews are both valid objects though.

Upvotes: 2

Views: 685

Answers (2)

Daniel
Daniel

Reputation: 9040

If you are calling self.collectionView registerClass..., then you need to remove it. Storyboards handle this registration automatically.

Upvotes: 1

Yan
Yan

Reputation: 3616

I don't think you need to use tags in this situation. You can create a UIImageView property in FeedViewCell wire it up in interface builder and then access it in 

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

For Example

// in the FeedViewCell

    @interface FeedViewCell  : UICollectionViewCell

    @property (weak, nonatomic) IBOutlet UIImageView *imageView;

    @end

// in the controller

    - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
        static NSString *identifier = @"Cell";

        FeedViewCell *cell = (FeedViewCell *) [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];

        cell.imageView.image = [UIImage imageNamed:[postPhotos objectAtIndex:indexPath.row]];
        return cell;
    }

Open up storyboard then click the assistant editor button which will bring up the another window. Open the feedViewCell.h there and ctrl+click on the imageView and drag it to the .h file that will give you a menu to create the outlet. You can give it the name to the imageView Property. That should be it. enter image description here

Check out this link for more info http://klanguedoc.hubpages.com/hub/IOS-5-A-Beginners-Guide-to-Storyboard-Connection

Upvotes: 1

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