How to make a stretchable header view collection view [Swift] - swift

Question

In my swift app I've a collection view and I want to creare a stretchable header view like this in table view: https://medium.com/if-let-swift-programming/how-to-create-a-stretchable-tableviewheader-in-ios-ee9ed049aba3

Answer 1

You already answered your question yourself with that article link, unless I miss something.
I will copy & paste for you and others that may have the same question, if it helps, because it even ships with a github link (kudos to Abhimuralidharan # Medium):
Create a tableview with the basic datasource and delegate methods which are required to simply load the table with some data.
Set the tableview’s contentInset property:
tableView.contentInset = UIEdgeInsetsMake(300, 0, 0, 0)
Here, I set the top value as 300 which is a calculated number which I will set as the initial normal height for the header imageview. Now, that we set the contentInset , the tableview’s frame will start at (0,0) and the first cell will start at (0,300).
Now, create an imageview with height 300 and add it to the current View above the tableview.
imageView.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: 300)
imageView.image = UIImage.init(named: “poster”)
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
view.addSubview(imageView)
Then, add the following code in the scrollview delegate method scrollViewDidScroll which gets called every time the tableview is scrolled.
func scrollViewDidScroll (_ scrollView: UIScrollView) {
let y = 300 — (scrollView.contentOffset.y + 300)
let height = min(max(y, 60), 400)
imageView.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: height)
}
Compile and run the code. Full source code is available in github.