UICollectionView inside TableViewCell not called

问题:

I have a UITableView contains one horizontal scroll UICollectionView in every cell like this

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! ServiceTypeCell
    cell.collectionView.delegate = self
    cell.collectionView.dataSource = self
    cell.lblName.text = serviceTypes[indexPath.row].name
    cell.tag = getTag(indexPath)
    print("uitableviewcell : \(indexPath)")
    return cell
}

And in every UICollectionViews

func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 1
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    let cell = collectionView.superview?.superview as! ServiceTypeCell
    let indexPath = getIndexPath(cell.tag)
    print("uitableviewcell from uicollectionview : \(indexPath)")
    return serviceTypes[indexPath.row].services.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let tableViewCell = collectionView.superview?.superview as! ServiceTypeCell
    let tableViewIndexPath = getIndexPath(tableViewCell.tag)
    let service = serviceTypes[tableViewIndexPath.row].services[indexPath.row]
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! ServiceTypeDetailCell
    cell.lblName.text = service.name
    return cell
}

My problem is UICollectionView Datasource only called between UITableViewCell index 0 to 3. Why does this happen?

My print debug result like this

uitableviewcell : [0, 0]
uitableviewcell from uicollectionview : [0, 0]
uitableviewcell : [0, 1]
uitableviewcell from uicollectionview : [0, 1]
uitableviewcell : [0, 2]
uitableviewcell from uicollectionview : [0, 2]
uitableviewcell : [0, 3]
uitableviewcell from uicollectionview : [0, 3]
uitableviewcell : [0, 4]
uitableviewcell : [0, 5]
uitableviewcell : [0, 6]

回答1:

This happens because your collection view instances are reused with cells. Only 4 instances are being created and reused.

You can write your collectionview logic in your custom tableview cell and make custom cell as delegate and datasource of collectionview.

回答2:

Not sure , whether this can Resolve your issue or not , but having consuming so much time finally i found the answer why CollectionView delgate method not gets called when it is embed inside TableView :

we basically use these two :

• UICollectionViewDataSource

• UICollectionViewDelegate

but forget to conform this : UICollectionViewDelegateFlowLayout

After conforming this (UICollectionViewDelegateFlowLayout) did solve my issue .

Hope it will solve other issue too. Feel free to comment and share your feedback. Thanks.

回答3:

Write collection view code on cell class. And give collectionview delegate to cell because cell is super class of collection view. Check this screen shot