单元重用tableview内collectionview中的另一个图像

Question

Currently,

I have a feed for the user and it uses uitableview and there is a uicollectionview inside tableview for multi-images.

'Like' or 'Comment' functions are working well but some issues happen when user taps 'Like'.

I do not want to show several changes, but when user taps 'Like', I need to reload a cell and it shows another picture for a short time(bcs of reuse) and back to original image.

I tried to use the function, prepareForReuse(). However, I am not sure how to maintain the same image currently on the screen when they are reloading. Any idea u have?

For ur more information, let me show my tableview's part of 'CellForItemAt' and collectionview's same method.

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "storyCell", for: indexPath) as! StoryPhotoCollectionViewCell

    let imageURL = photoList[indexPath.row]
    let url = URL(string: imageURL)

    DispatchQueue.main.async {
        cell.imageView.kf.setImage(with: url, placeholder: #imageLiteral(resourceName: "imageplaceholder"), options: nil, progressBlock: nil, completionHandler: nil)
    }

    cell.imageView.kf.indicatorType = .activity

    return cell
}

The collectionView's datasource is photoList array, so in the tableview, I have this code.

DispatchQueue.main.async { 
        cell.photoList = (story.imageArray?.components(separatedBy: ",").sorted())!
    }

Answer 1

The issue should be due to delay in asynchronous download of the image,

I believe your code would be like this

 cell.image = downloadFromURL(SOME_URL)

Add this single line code before assigning the image

cell.image = nil; // or some placeholder image
cell.image = downloadFromURL(SOME_URL)

If possible please provide more info

Answer 2

If I understand well your question, you need:

1. When the status change, you change the image so, this image can be stored as part of the app or external. If it is the same image, you need to keep it cached.

2. You start a timer like:

   let countTimeBeforeChangeMyImageBack = DispatchTime.now() + .seconds(waitTimeBeforeStartCounting)

   DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute: { self.YourMethodToChangeYourImageBack })

3. At your method YourMethodToChangeYourImageBack you set the original image back. Here, remember you could need to join back to the main thread before updating the UI:

   // Re join the main queue after the callback DispatchQueue.main.sync() { // Your code to update the image }

Hope it Helps.