I got some issues with the following code: I created a custom Cell with a Custom UICollectionView class. I used Xib files instead of the storyboard.
It never calls the didSelectItemAtIndexPath method but why? I am really desperate :'(.
import UIKit
class CustomCollectionView: UICollectionView, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
var refreshControl : UIRefreshControl = UIRefreshControl()
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.delegate = self
self.dataSource = self
var flowLayout:UICollectionViewFlowLayout = UICollectionViewFlowLayout()
flowLayout.scrollDirection = UICollectionViewScrollDirection.Vertical
self.collectionViewLayout = flowLayout
self.refreshControl.addTarget(self, action: "refreshData:", forControlEvents: UIControlEvents.ValueChanged)
self.addSubview(refreshControl)
self.userInteractionEnabled = true
self.registerClass(CustomCollectionViewCell.self, forCellWithReuseIdentifier: "outfit")
self.registerNib(UINib(nibName: layoutHelper.getCellXibName("CustomCollectionViewCell"), bundle: nil), forCellWithReuseIdentifier: "outfit")
self.backgroundColor = UIColor.whiteColor()
}
//
// MARK: UICollectionViewDataSource - Methods
//
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
var cell : CustomCollectionViewCell = collectionView.dequeueReusableCellWithReuseIdentifier("outfit", forIndexPath: indexPath) as! CustomCollectionViewCell
cell.label.text = "Outfit #" + String(indexPath.row)
let url = NSURL(string: "http://placehold.it/177x370")
cell.imageView.sd_setImageWithURL(url, completed: nil)
return cell
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
println("at index path %i", indexPath.row)
}
Related
I have a UICollectionView inside a UICollectionViewCell, and a separate NSObject that is the dataSource. I am able to set the dataSource for the external UICollectionView, but not the internal one.
Here's the cell containing the internal UICollectionView:
class FeaturedCell: UICollectionViewCell, UICollectionViewDelegate {
#IBOutlet var collectionView: UICollectionView!
let data = FeaturedData()
override init(frame: CGRect) {
super.init(frame: frame)
//setUp()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
func setUp() {
collectionView.dataSource = data
collectionView.delegate = self
collectionView.reloadData()
}
}
extension FeaturedCell {
func setCollectionViewDataSourceDelegate <D: FeaturedData> (_ dataSourceDelegate: D, forRow row: Int) {
collectionView.delegate = dataSourceDelegate
collectionView.dataSource = dataSourceDelegate
collectionView.reloadData()
print("Reload Data")
}
}
And the UIView containing the external UICollectionView:
class MainView: UIView, UICollectionViewDelegate {
#IBOutlet var collectionView: UICollectionView!
let data = MainData()
override func awakeFromNib() {
setUp()
}
func setUp() {
collectionView.dataSource = data
collectionView.delegate = self
collectionView.backgroundColor = UIColor.orange
collectionView.collectionViewLayout = createLayout()
collectionView.isPagingEnabled = true
collectionView.bounces = false
collectionView.allowsSelection = true
}
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
print("WillDisplay")
guard let cell: FeaturedCell = collectionView.dequeueReusableCell(withReuseIdentifier: "FeaturedCell", for: indexPath) as? FeaturedCell else {
fatalError("Unable to dequeue FeaturedCell.")
}
cell.setCollectionViewDataSourceDelegate(featuredData, forRow: indexPath.item)
}
}
Both of these methods are being called, but the dataSource and delegates are never being set. I also followed this tutorial exactly (with a UITableView, even) and it still would not set the dataSource or delegate. What am I doing wrong?
I think this will help
class FeaturedCell: UICollectionViewCell {
#IBOutlet var collectionView: UICollectionView!
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
}
extension FeaturedCell {
func setCollectionViewDataSourceDelegate <T: UICollectionViewDelegate , D: FeaturedData> (delegate: T dataSource: D, forRow row: Int) {
collectionView.delegate = delegate
collectionView.dataSource = dataSource
collectionView.reloadData()
print("Reload Data")
}
}
and in the MainView
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
print("WillDisplay")
guard let cell: FeaturedCell = collectionView.dequeueReusableCell(withReuseIdentifier: "FeaturedCell", for: indexPath) as? FeaturedCell else {
fatalError("Unable to dequeue FeaturedCell.")
}
cell.setCollectionViewDataSourceDelegate(self, featuredData, forRow: indexPath.item)
}
And for the tutorial you followed this a Github link for the tutorial, compare your code with that and see where did you missed out.
Hope this will helps.
Solved it. The problem was that this:
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
print("WillDisplay")
guard let cell: FeaturedCell = collectionView.dequeueReusableCell(withReuseIdentifier: "FeaturedCell", for: indexPath) as? FeaturedCell else {
fatalError("Unable to dequeue FeaturedCell.")
}
cell.setCollectionViewDataSourceDelegate(featuredData, forRow: indexPath.item)
}
Needed to be changed to this:
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
print("WillDisplay")
guard let featuredCell = cell as? FeaturedCell else { return }
featuredCell.setCollectionViewDataSourceDelegate(featuredData, forRow: indexPath.item)
}
I need to implement horizontal UICollectionView.
Sometimes, I need to update the data, So I decided to implement a refreshcontrol.
I called reloadData() with refreshcontrol. It seems to be working, but cellForItemAt is not called the correct time.
So, when the cell count has changed it will be crashed.
class ViewController: UIViewController, UICollectionViewDelegate {
#IBOutlet weak var collectionView: UICollectionView!
private let refreshControl = UIRefreshControl()
private var cellCount = 1
override func viewDidLoad() {
super.viewDidLoad()
collectionView.delegate = self
collectionView.dataSource = self
collectionView.refreshControl = refreshControl
refreshControl.addTarget(self, action: #selector(refresh(sender:)), for: .valueChanged)
collectionView.register(UINib(nibName: "TopCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "Cell")
if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
layout.scrollDirection = .horizontal // not working
// layout.scrollDirection = .vertical //working
}
}
#objc func refresh(sender: UIRefreshControl) {
cellCount = cellCount + 1
collectionView.reloadData()
sender.endRefreshing()
}
}
extension ViewController: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return cellCount
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: TopCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! TopCollectionViewCell
return cell
}
}
If the direction change to vertical, it is working.
Is it correct behavior? or just a bug?
Set the alwaysBounceVertical property of collectionView as true in viewDidLoad(), i.e.
collectionView.alwaysBounceVertical = true
I have build a UICollectionViewController programmatically which returns 4 cells. HomeCell, TrendingCell, SubscriptionCell and AccountCell.
All 4 cells should be different and you can scroll them horizontally. <--->.
class HomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout{
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.register(HomeCell.self, forCellWithReuseIdentifier: homeCellId)
collectionView?.register(TrendingCell.self, forCellWithReuseIdentifier: trendingCellId)
collectionView?.register(SubscriptionCell.self, forCellWithReuseIdentifier: subscriptionCellId)
collectionView?.register(AccountCell.self, forCellWithReuseIdentifier: accountCellId)
}
}
Lets take the first cell of the HomeController called HomeCell to illustrate my problem. Homecell has three custom cells called VideoCell, CategoryCell and UserSearchCell.
class HomeCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
let searchId = "sarchId"
let scrollId = "scrollId"
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = UIColor.white
cv.dataSource = self
cv.delegate = self
return cv
}()
override func setupViews() {
super.setupViews()
.....
// register three different cells within HomeCell
collectionView.register(VideoCell.self, forCellWithReuseIdentifier: cellId)
collectionView.register(CategoryCell.self, forCellWithReuseIdentifier: scrollId)
collectionView.register(UserSearchCell.self, forCellWithReuseIdentifier: searchId) //
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
In HomeCell I register the UserSearchCell as third cell.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.item == 0 {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "videoId", for: indexPath)
} else if indexPath.item == 1{
cell = collectionView.dequeueReusableCell(withReuseIdentifier: categoryId, for: indexPath)
}else {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: searchId, for: indexPath)
}
return cell
}
If I click on that element my goal is to push a new ViewController to the navigationController. But I have no access and don't know how to change the view within that nested structure. I tried the didSelectItem method within HomeCell class and was able to print something the console when clicking the third cell but couldn't change the view.
class HomeCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.item == 2 {
print(123)
}
....
}
Please help. Is there a way to change the View within the didSelectItem method of HomeCell ??
You need to write a protocol to refer back to your HomeController.
protocol HomeCellProtocol {
func pushNavigation(_ vc: UIViewController)
}
add write delegate property to HomeCell class with
class HomeCell: ..... {
var delegate: HomeCellProtocol?
}
and make HomeController confirm to HomeCellProtocol with
extention HomeController: HomeCellProtocol {
func pushNavigation(_ vc: UIViewController) {
self.navigationController?.pushViewController(vc, animated: true)
}
}
and when you setup your HomeCell you need to set your delegate in HomeController
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: homeCellId, for: indexPath) as HomeCell;
cell.delegate = self // Set the delegate
return cell
}
finally, you can call push function within HomeCell with
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.item == 2 {
let vc = UIViewController();
self.delegate?.pushNavigation(vc);
}
}
I created a UICollectionView as a major UICollectionView and each collectionViewCell has another UICollectionView "B" as it's subview
Then I add a tapGesture in "B". but "B" can't trigger this gesture.
Following is my main code:
Main UICollectionView
import Foundation
import UIKit
class mainViewController :UIViewController,UICollectionViewDataSource,UICollectionViewDelegate {
#IBOutlet weak var mainCollectionView: UICollectionView!
override func viewDidLoad() {
self.mainCollectionView.registerNib(UINib(nibName: "OuterCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "OuterCollectionViewCell")
self.mainCollectionView.delegate = self
self.mainCollectionView.dataSource = self
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return 1
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("OuterCollectionViewCell", forIndexPath: indexPath) as! OuterCollectionViewCell
return cell
}
}
UICollectionView B:
class OuterCollectionViewCell: UICollectionViewCell,UICollectionViewDataSource, UICollectionViewDelegate {
#IBOutlet weak var InnerCollectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
InnerCollectionView.registerNib(UINib(nibName: "InnerCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "CellInner")
}
func handleTapGesture(sender: UITapGestureRecognizer) {
print("tapguesture")
}
override func didMoveToWindow(){
let tapGesture = UITapGestureRecognizer(target: self, action: "handleTapGesture:")
InnerCollectionView.backgroundColor = UIColor.redColor()
InnerCollectionView.addGestureRecognizer(tapGesture)
InnerCollectionView.delegate = self
InnerCollectionView.dataSource = self
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CellInner", forIndexPath: indexPath) as! InnerCollectionViewCell
return cell
}
}
This issue is bugging me an whole day. Is there anyone who has any ideas about how to fix this issue?
I have uploaded the project into github: https://github.com/dengchicheng/Test2
update－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
today I init the innerCollectionView by code programmably instead of init by NIB. and it works
let flowLayout = UICollectionViewFlowLayout()
flowLayout.scrollDirection = UICollectionViewScrollDirection.Horizontal
let InnerCollectionView = UICollectionView(frame: CGRect(x: 0, y: 0, width: 800, height: 600), collectionViewLayout: flowLayout)
I don't know what the NIB did to the UIcollectionview
I did set the userInteractive to be true in the interface builder
I am interested in having a collectionview as a part of a collection view cell but for some reason cannot figure out how this would be done. Where would I implement the necessary methods for the cells collectionview?
There's an article that Ash Furrow wrote that explains how to put an UICollectionView inside an UITableViewCell. It's basically the same idea when using it inside an UICollectionViewCell.
Everything is done programatically. No storyboards.
I added a UICollectionView inside my UICollectionViewCell. I also show how to add again a UICollectionViewCell inside the created UICollectionView to have this result
import UIKit
class CategoryCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
private let cellId = "cell"
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let appsCollectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
return collectionView
}()
func setupViews() {
backgroundColor = .blue
addSubview(appsCollectionView)
appsCollectionView.delegate = self
appsCollectionView.dataSource = self
appsCollectionView.register(AppCell.self, forCellWithReuseIdentifier: cellId)
addConstrainstWithFormat("H:|-8-[v0]-8-|", views: appsCollectionView)
addConstrainstWithFormat("V:|[v0]|", views: appsCollectionView)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
}
class AppCell: UICollectionViewCell {
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupViews(){
backgroundColor = .red
}
}
My UICollectionViewController
import UIKit
class FeaturedAppsController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let cellId = "cell"
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
collectionView?.backgroundColor = .white
collectionView?.register(CategoryCell.self, forCellWithReuseIdentifier: cellId)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(view.frame.width, 150)
}
}
The whole explanation can be found and was developed by "Let´s build that app": https://www.youtube.com/watch?v=Ko9oNhlTwH0&list=PL0dzCUj1L5JEXct3-OV6itP7Kz3tRDmma
This is too late for this answer but it might help others. This is an example of UICollectionView inside a UICollectionViewCell.
Lets start by having a mainCollectionView. Then on each cell of this collection create and initialize a new UICollectionView and right place to do that is in this following delegate of UICollectionView
func collectionView(collectionView: UICollectionView, willDisplayCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: NSIndexPath)
e.g I initialize the MainCollectionViewCell here and then MainCollectionViewCell handles the logic to create a new UICollectionView
guard let collectionViewCell = cell as? MainCollectionViewCell else { return }
collectionViewCell.delegate = self
let dataProvider = ChildCollectionViewDataSource()
dataProvider.data = data[indexPath.row] as NSArray
let delegate = ChildCollectionViewDelegate()
collectionViewCell.initializeCollectionViewWithDataSource(dataProvider, delegate: delegate, forRow: indexPath.row)
collectionViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0
Here is the initializer on MainCollectionViewCell that creates a new UICollectionView
func initializeCollectionViewWithDataSource<D: protocol<UICollectionViewDataSource>,E: protocol<UICollectionViewDelegate>>(dataSource: D, delegate :E, forRow row: Int) {
self.collectionViewDataSource = dataSource
self.collectionViewDelegate = delegate
let flowLayout = UICollectionViewFlowLayout()
flowLayout.scrollDirection = .Horizontal
let collectionView = UICollectionView(frame: self.bounds, collectionViewLayout: flowLayout)
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseChildCollectionViewCellIdentifier)
collectionView.backgroundColor = UIColor.whiteColor()
collectionView.dataSource = self.collectionViewDataSource
collectionView.delegate = self.collectionViewDelegate
collectionView.tag = row
self.addSubview(collectionView)
self.collectionView = collectionView
collectionView.reloadData()
}
Hope that helps !!
I did an example for this and put in on github. It demonstrates the use UICollectionView inside a UICollectionViewCell.
https://github.com/irfanlone/Collection-View-in-a-collection-view-cell
Easiest solution for collectionview inside collectionview using storyboard and Swift 5
Please refer this link for nested collectionview example
import UIKit
class ParentViewController:UIViewController,UICollectionViewDataSource,UICollectionViewDelegate {
//MARK: Declare variable
//MARK: Decalare outlet
#IBOutlet weak var outerCollectionView: UICollectionView!
#IBOutlet weak var pageControl: UIPageControl!
let outerCount = 4
//MARK: Decalare life cycle methods
override func viewDidLoad() {
super.viewDidLoad()
pageControl.numberOfPages = outerCount
}
//MARK: Collection View delegate methods
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return outerCount
}
//MARK: Collection View datasource methods
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "OuterCell", for: indexPath) as! OuterCollectionViewCell
cell.contentView.backgroundColor = .none
return cell
}
//MARK:- For Display the page number in page controll of collection view Cell
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let visibleRect = CGRect(origin: self.outerCollectionView.contentOffset, size: self.outerCollectionView.bounds.size)
let visiblePoint = CGPoint(x: visibleRect.midX, y: visibleRect.midY)
if let visibleIndexPath = self.outerCollectionView.indexPathForItem(at: visiblePoint) {
self.pageControl.currentPage = visibleIndexPath.row
}
}
}
class OuterCollectionViewCell: UICollectionViewCell ,UICollectionViewDataSource,UICollectionViewDelegate {
#IBOutlet weak var InnerCollectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
InnerCollectionView.delegate = self
InnerCollectionView.dataSource = self
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
6
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "InnerCell", for: indexPath) as! InnerCollectionViewCell
cell.contentView.backgroundColor = .green
return cell
}
}
class InnerCollectionViewCell: UICollectionViewCell{
}