Pull to refresh in UICollectionView in ViewController - ios

Question

I used the following code at a UICollectionViewController
override func viewDidLoad() {
self.collectionView!.alwaysBounceVertical = true
let refresher = UIRefreshControl()
refresher.addTarget(self, action: "refreshStream", forControlEvents: .ValueChanged)
refreshControl = refresher
collectionView!.addSubview(refreshControl!)
}
func refreshStream() {
print("refresh")
self.collectionView?.reloadData()
refreshControl?.endRefreshing()
}
Now I need it to work with a UICollectionView inside a UIViewController and I googled for an hour now but can't get it working.
I appreciate any help.

Answer 1

New swift code changed in calling action method you could do rewrite like this
#IBOutlet weak var collectionView: UICollectionView!
var refresher:UIRefreshControl!
override func viewDidLoad() {
super.viewDidLoad()
self.refresher = UIRefreshControl()
self.collectionView!.alwaysBounceVertical = true
self.refresher.tintColor = UIColor.red
self.refresher.addTarget(self, action: #selector(loadData), for: .valueChanged)
self.collectionView!.addSubview(refresher)
}
#objc func loadData() {
self.collectionView!.refreshControl.beginRefreshing()
//code to execute during refresher
.
.
.
stopRefresher() //Call this to stop refresher
}
func stopRefresher() {
self.collectionView!.refreshControl.endRefreshing()
}

Answer 2

Swift 5 solution
As #fishspy already mentioned, that's the way to put your collection view inside a view controller, but I'm gonna share also how to connect your refresh control to the collection view in a cleaner way.
Since iOS 10 there's a dedicated property for the refresh control. Apart of that, I'd also recommend to directly initialise your refresh control as a property, declaring it private and doing the following things:
#IBOutlet private weak var collectionView: UICollectionView!
private let refreshControl = UIRefreshControl()
override func viewDidLoad() {
super.viewDidLoad()
refreshControl.addTarget(self, action: #selector(didPullToRefresh(_:)), for: .valueChanged)
collectionView.alwaysBounceVertical = true
collectionView.refreshControl = refreshControl // iOS 10+
}
#objc
private func didPullToRefresh(_ sender: Any) {
// Do you your api calls in here, and then asynchronously remember to stop the
// refreshing when you've got a result (either positive or negative)
refreshControl.endRefreshing()
}

Answer 3

var refreshControl:UIRefreshControl!
override func viewDidLoad() {
super.viewDidLoad()
self.refreshControl = UIRefreshControl()
self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
self.refreshControl.addTarget(self, action: #selector(PricingPlansCollectionViewController.reload), for: .valueChanged)
collectionView!.addSubview(refreshControl)
}
func refresh(sender:AnyObject)
{
//DO
}

Answer 4

From the storyboard, you need to link the collection view to the appropriate controller file, using Ctrl + Drag from the collection view object. It needs to be linked via an #IBOutlet.
Also, you should Ctrl + Drag from the collection view to the view controller object on the storyboard and select Data Source and Delegate so that the collection view is correctly linked.
Let me know if this helps or if I have misunderstood your situation.

Answer 5

For me, i had:
func setupCollectionView(){
self.refreshControl = UIRefreshControl()
self.refreshControl.attributedTitle = NSAttributedString(string: "Refreshing content...")
self.refreshControl.addTarget(self, action: #selector(self.reload), for: .valueChanged)
collectionView!.addSubview(refreshControl)
}
It still wasn't working (I believe i had constraints preventing it somehow), so i added:
collectionView.alwaysBounceVertical = true
then all was good. Just in case someone else is facing the same issue.
For a better understanding, the full implementation
#IBOutlet private weak var collectionView: UICollectionView!
let refreshControl = UIRefreshControl()
override func viewDidLoad() {
super.viewDidLoad()
setupCollectionView()
}
func setupCollectionView(){
collectionView.delegate = self
collectionView.dataSource = self
collectionView.alwaysBounceVertical = true
self.refreshControl = UIRefreshControl()
self.refreshControl.attributedTitle = NSAttributedString(string: "Refreshing content...")
self.refreshControl.addTarget(self, action: #selector(self.refresh), for: .valueChanged)
collectionView!.addSubview(refreshControl)
}
#objc func refresh(_ sender:AnyObject) {
//do refreshing stuff
}

Answer 6

private let refreshControl = UIRefreshControl()
refreshControl.addTarget(self, action: #selector(youFunction), for: .valueChanged)
refreshControl.attributedTitle = NSAttributedString(string: "Fetching Data ...", attributes: nil)
DispatchQueue.main.async {
self.refreshControl.endRefreshing()
yourCollectionViewOrTableView.reloadData()
}