custom cell and custom height for each - swift

Question

I output 4 custom cells via the switch function now I need to output either a dynamic height value or a fixed height value for each of them. I like both, as their height is always static.
I subscribed to The uiСollectionviewВelegateFlowLayout Protocol and found how to change the height of all cells
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let size = CGSize(width: 357, height: 600)
return size
to override the height of individual cells I use the function
cell.frame = CGRect(cell.frame.origin.x, cell.frame.origin.y, width: 100.0, height: 100.0)
but it doesn't work, "Expression type '#lvalue CGRect' is ambiguous without more context"
what should I do in this case? what function to use?
full code below
// main protocols UICollectionView
extension ViewController: UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
// width and height for cell in collectionView
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let size = CGSize(width: 357, height: 600)
return size
}
//margins for cell in collectionView
func collectionView(_ collectionView: UICollectionView, layout
collectionViewLayout: UICollectionViewLayout,
minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 40.0
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 4
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
var cell: UICollectionViewCell!
switch indexPath.row {
case 1:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "secondCell", for: indexPath)
as? secondCollectionViewCell
cell.frame = CGRect(cell.frame.origin.x, cell.frame.origin.y, width: 100.0, height: 100.0)
case 2:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "thirdCell", for: indexPath)
as? cellThirdCollectionViewCell
case 3:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "fourthCell", for: indexPath)
as? fourthCollectionViewCell
default:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath)
as? imageModelCollectionViewCell
}
return cell
}
}

Answer 1

extension ViewController : UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
switch indexPath.row {
case 1:
return CGSize(width: 100, height: 200)
case 2:
return CGSize(width: 100, height: 300)
case 3:
return CGSize(width: 100, height: 400)
default:
return CGSize(width: 100, height: 100)
}
}
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
var cell: UICollectionViewCell!
switch indexPath.row {
case 1:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "firstCell", for: indexPath)
as? firstCollectionViewCell
case 2:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "secondCell", for: indexPath)
as? secondCollectionViewCell
case 3:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "thirdCell", for: indexPath)
as? thirdCollectionViewCell
default:
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath)
as? imageModelCollectionViewCell
}
return cell
}
}
completely solves the problem
don't forget add
override func viewDidLoad() {
super.viewDidLoad()
collectionView.delegate = self
}
p.s. If You get an error with "collectionView.delegate = self" is a possible reason that you are working in a viewController and not in a collectionViewController
You need to add IBOutlet

Answer 2

Have you tried changing your function func collectionView(_:layout:sizeForItemAt:) to something like this?
let cellHeights = [ 90, 400, 100, 70 ]
// width and height for cell in collectionView
func collectionView( _ view: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath ) -> CGSize
{
return CGSize(
width: view.bounds.size.width,
height: cellHeights[indexPath.row]
)
}
Also, casting the result of collectionView.dequeueReusableCell(withReuseIdentifier:for:) to a UICollectionViewCell subclass has no effect in your code...
I might change it to something like:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
// map row numbers to cell reuse identifiers...
let ids = [
0: "secondCell",
1: "thirdCell",
2: "fourthCell"
]
// look up the reuse identifier for the row we want; if none found (subscript call returns `nil`), use `"imageCell"`
let reuseID = ids[indexPath.row] ?? "imageCell"
let cell = collectionView.dequeueReusableCell( withReuseIdentifier: reuseID, for: indexPath)
return cell
}

Answer 3

you can use array of height and retrieve cell height based on indexPath.
let heightArray = [90,400,100,70]
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 357, height: heightArray[indexPath.row])
}