TableView Items get refresh on scrolling - ios

Question

Having UICollectionView as a child of UITableView row. UICollectionView contains images, but whenever I scroll tableview down and up the collection view images got vanished randomly. I am attaching images for my problem reference. Please suggest me how to stop this.
I want my tableview to be like this. And its items should not change on scrolling.
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The collectionview images got vanish on scrolling tableview. It looks like this after scrolling up.
Code Is as follow:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let cell:PartOfLookTableViewCell = self.looksListTable.dequeueReusableCell(withIdentifier: "cell") as! PartOfLookTableViewCell
let oneRecord = looksArray[indexPath.row]
cell.myCollectionView.loadInitial(_dataArray: oneRecord.imagesArray, isLooks: 1)
return cell
}
Code for loading data to CollectionView:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: looksReuseIdentifier, for: indexPath) as! CustomCollectionViewCell
let oneRecord = inputArray[indexPath.row]
cell.productImage.sd_setImage(with: URL.init(string: oneRecord.thumb_url)){ (image, error, cacheType, url) in
DispatchQueue.main.async {
cell.productImage.image = image
}
}
}
}
}

Answer 1

#Sourabh Bissa :
UITableView reuses the cell using method CellForRowAtIndexPath whenever your new cell gets visible your this method reuse the data source.
The very important thing here is to maintain the data source:
In your case cell for the row at index path giving the updated value to the collection view method but you are not reloading in main Queue. Try to do it immediately after you get the data source.
Your Cell for the row at index path will look like this :
guard let cell = self.tableview.dequeueReusableCell(withIdentifier: "cell") as! PartOfLookTableViewCell else {
return UITableViewCell()
}
let oneRecord = looksArray[indexPath.row]
cell.configureCell(for record : oneRecord with looks : 1)
return cell
and Now in the cell, you will have collection view outlet, where you will implement a collection view data source method and there you download your images asynchronously.
Cell Class will look like this :
class PartOfLookTableViewCell: UITableViewCell {
#IBOutlet weak var collectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
collectionView.delegate = self
collectionView.dataSource = self
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
func configureCell(for record : Record , with looks : Int) {
// Here reload your collection view
// This collection view will be specific to the cell.
collectionView.reloadData()
}
}
extension PartOfLookTableViewCell : UICollectionViewDelegate , UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
//return array
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
// Asyncronously download images
}
}
This is how you can achieve your requirements without using any tags. Please let me know if you have any Queries in it.