#IBOutlet weak var collectionView: UICollectionView!
var model = CardModel()
//Kepp track of the cards veiwed
var cardArray = [Card]()
override func viewDidLoad() {
super.viewDidLoad()
//Call the getCards method of the card model
cardArray = model.getCards()
collectionView.delegate = self
collectionView.dataSource = self
}
// MARK: -UICOlecctionView Protocol Methods
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return cardArray.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
// Get a card CardCollectionViewCell object
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CardCell", for: indexPath) as! CardCollectionViewCell
//Get the card that the collection view is trying to display
let card = cardArray [indexPath.row]
//Set the card for the cell
cell.setCard(card)
return cell
}
func collectionView( _ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Cell is taped: \(indexPath.row)")
let cell = collectionView.cellForItem(at: indexPath) as! CardCollectionViewCell
// Flip the card
cell.flip()
}
}
I have an issue when I tap on the card to flip. The did select function is not getting called as I tested it for a print function and it shows that it's not tapping at all. Can some help please?
Related
I am using collectionview in tableview cell,
i need to pass selected collectionview cells value to next viewcontroller, how?
code: here is the code for tableview and collectionview cell
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CategoryNewTableCell", for: indexPath) as! CategoryNewTableCell
let indexData = self.activeCategories?[indexPath.row]
cell.selectionStyle = .none
cell.catNameLbl.text = indexData?.details?.first?.title
cell.subCategories = indexData?.sub_categories
cell.clcSeller.reloadData()
}
class CategoryNewTableCell: UITableViewCell,UICollectionViewDelegate,UICollectionViewDataSource{
#IBOutlet weak var clcSeller: UICollectionView!
public var subCategories : Array<Sub_categories>?
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return subCategories?.count ?? 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "SubCatCollectionCell", for: indexPath) as! SubCatCollectionCell
let subCategory = self.subCategories?[indexPath.item]
cell.lblTitle.text = langType == .en ? subCategory?.details?.first?.title : subCategory?.details?[1].title
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let vc = StoryBoard.main.instantiateViewController(withIdentifier: "SearchResultVC") as! SearchResultVC
vc.subCatId = sub_categories?[indexPath.row].slug ?? ""
self.navigationController?.pushViewController(vc, animated: true)
}
}
here if i use didSelectItemAt for collectionview to send its selected cell value to next view controller
error:
Value of type 'CategoryNewTableCell' has no member 'navigationController'
if i give button action in main class then able to push but value is not going
class CategoryNewVC: UIViewController {
#IBAction func didselectcollectionviewBTn(_ sender: UIButton) {
let vc = StoryBoard.main.instantiateViewController(withIdentifier: "SearchResultVC") as! SearchResultVC
vc.subCatId = //here how to pass value
self.navigationController?.pushViewController(vc, animated: true)
}
}
here how to pass selected collectionview cells value to SearchResultVC please do help
EDIT
according to below answer i have added: still didSelectItemAt not called, why plz do help
class CategoryNewTableCell: UITableViewCell,UICollectionViewDelegate,UICollectionViewDataSource{
override func awakeFromNib() {
super.awakeFromNib()
self.clcSeller.delegate = self
self.clcSeller.dataSource = self
//
You can use protocol to send data to your nextviewcontroller.
protocol CategorySelectionDelegate {
func get(category: Sub_categories)
}
Declare the delegate in your CategoryNewTableCell and use it in didSelectItemAt method of your collectionviewcell like below:
class CategoryNewTableCell:
UITableViewCell,UICollectionViewDelegate,UICollectionViewDataSource{
#IBOutlet weak var clcSeller: UICollectionView!
public var subCategories : Array<Sub_categories>?
var delegate: CategorySelectionDelegate?
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return subCategories?.count ?? 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "SubCatCollectionCell", for: indexPath) as! SubCatCollectionCell
let subCategory = self.subCategories?[indexPath.item]
cell.lblTitle.text = langType == .en ? subCategory?.details?.first?.title : subCategory?.details?[1].title
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
delegate?.get(category: sub_categories?[indexPath.row])
}
}
Adopt the protocol in the receiving class
class CategoryNewVC: UIViewController, CategorySelectionDelegate {
func get(category: Sub_categories) {
let vc = StoryBoard.main.instantiateViewController(withIdentifier: "SearchResultVC") as! SearchResultVC
vc.subCatId = category.slug ?? ""
self.navigationController?.pushViewController(vc, animated: true)
}
}
Declare a callback in the tableViewCell subclass.
class CategoryNewTableCell: UITableViewCell {
var onSelectSubcategory: ((_ subcategoryID: String) -> Void)?
}
Assign this callback in your cellForRow like this.
cell.subCategories = indexData?.sub_categories
cell.onSelectSubcategory = { [weak self] (subcategoryID) in
let vc = StoryBoard.main.instantiateViewController(withIdentifier: "SearchResultVC") as! SearchResultVC
vc.subCatId = subcategoryID
self?.navigationController?.pushViewController(vc, animated: true)
}
Invoke this callback from collectionView didSelectItem like this.
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let subcategoryID = sub_categories?[indexPath.item].slug ?? ""
self.onSelectSubcategory?(subcategoryID)
}
I am new to iOS and I want to implement a UICollectionView inside a UITableView which can have multiple select/unselect in section 1 of the UITableview. And in section 2, only a single selection is allowed. And save the selection sate event if I dismiss the Viewcontroller and when I open it again, it must show the last selected cell as highlight.
I searched for tutorials but all of them don't mention to select/unselect the state of collection cell or saving state after dismissing view controller.
Can someone help to implement it?
Thank in advance!
Here is my code I do till now:
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return clvData.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "clvCell", for: indexPath) as! demoCollectionViewCell
cell.title.text = clvData[indexPath.item] as? String
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath)
cell?.backgroundColor = .red
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath)
cell?.backgroundColor = .white
}
you guys can also check my project here:
https://mega.nz/#!xRs0EQyQ
try this and let me know if you have any problem or if this solved your problem.
var arrSelectedIndex:[IndexPath] = []// store this array either in database by api or in local
var clvData:[String] = []// your data array
//get the arrSelectedIndex from default in viewDidLoad before reloading the table and collection.
override func viewDidLoad() {
super.viewDidLoad()
if let myArray = UserDefaults.standard.array(forKey: "selectedArray") as? [IndexPath] {
arrSelectedIndex = myArray
} else {
arrSelectedIndex = []
}
}
// and save the arrSelectedIndex in viewWillDisappear method
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
UserDefaults.standard.set(arrSelectedIndex, forKey: "selectedArray")
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return clvData.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "clvCell", for: indexPath) as! demoCollectionViewCell
cell.title.text = clvData[indexPath.item] as? String
if arrSelectedIndex.contains(indexPath) { // You need to check wether selected index array contain current index if yes then change the color
cell.backgroundColor = UIColor.red
}
else {
cell.backgroundColor = UIColor.white
}
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath)
cell?.backgroundColor = .red
if !arrSelectedIndex.contains(indexPath) {// if it does not contains the index then add it
arrSelectedIndex.append(indexPath)
}
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath)
cell?.backgroundColor = .white
if let currIndex = arrSelectedIndex.firstIndex(of: indexPath) {// if it contains the index then delete from array
arrSelectedIndex.remove(at: currIndex)
}
}
In my match app Xcode project I have an error stating:
Use of unresolved identifier 'cell'.
My Code:
import UIKit
class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
}
#IBOutlet weak var collectionView: UICollectionView!
var model = CardModel()
var cardArray:[Card] = []
override func viewDidLoad() {
super.viewDidLoad()
//call the getCards method of the card model
cardArray = model.getCards()
collectionView.delegate = self
collectionView.dataSource = self
}
//mark: -UICollectionView Protocol Methods
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return cardArray.count
}
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
//get a cardCollectionViewcell object
let cell =
collectionView.dequeueReusableCell(withReuseIdentifier: "CardCell", for: indexPath) as! CardCollectionViewCell
//get card that
let card = cardArray[indexPath.row]
cell.setCard(card)
return
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
_ = collectionView.cellForItem(at: indexPath) as!CardCollectionViewCell
//flip the card
cell.flip() <--------- THIS IS THE ERROR
Once the error is fixed I am supposed to be able run a match app example on the fake iPhone. It would allow me to flip the cards on a click.
I think you forgot to set reusable identifier
I hope this will be resolve your issue.
To access that cell method you have to declare variable
let cell = collectionView.cellForItem(at: indexPath) as!CardCollectionViewCell
First of all you are misusing collectionView:willDisplay:forItemAt. Move everything into collectionView:cellForItemAt, replace return with return cell and delete willDisplay:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CardCell", for: indexPath) as! CardCollectionViewCell
//get card that
let card = cardArray[indexPath.row]
cell.setCard(card)
return cell
}
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) { ... }
The error is pretty clear: You never declared cell is the scope of didSelectItemAt. Change
let cell = collectionView.cellForItem(at: indexPath) as! CardCollectionViewCell
Have an issue where:
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
is called when an item is selected, but I cannot change any cell properties from this method.
I created a new project with a stripped down UICollectionViewController to change the background color of a cell when selected. It also doesn't work. Here it is:
import UIKit
private let reuseIdentifier = "Cell"
class CollectionViewController: UICollectionViewController {
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath)
cell.backgroundColor = UIColor.blue
return cell
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = self.collectionView(self.collectionView, cellForItemAt: indexPath)
cell.backgroundColor = UIColor.green
}
}
The only thing I did in Storyboard is delete the standard View Controller and replace it with a UICollectionViewController, create a subclass of UICollectionViewController and set the controller in the storyboard as that class.
Also, I can confirm that the cell's index path is returned from this method when called from inside the didSelectItemAt method:
self.collectionView.indexPathsForSelectedItems
You are using the wrong API. Never call the delegate method collectionView(_ cellForItemAt:, use cellForItem(at:
if let cell = collectionView.cellForItem(at: indexPath) {
cell.backgroundColor = UIColor.green
}
But be aware that this change is not persistent. When the user scrolls the color will change back to blue.
You can achieve that as below,
ViewController
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ColoursViewCell", for: indexPath) as! ColoursViewCell
return cell
}
UICollectionViewCell
class ColoursViewCell: UICollectionViewCell {
#IBOutlet var photoImageView: UIImageView?
override var bounds: CGRect {
didSet {
self.layoutIfNeeded()
}
}
override var isSelected: Bool{
didSet{
if self.isSelected{
self.photoImageView?.backgroundColor = UIColor.random
}else{
self.photoImageView?.backgroundColor = UIColor.lightGray
}
}
}
}
you can have sample projects from this link I have in GitHub
https://github.com/hadanischal/RandomColors/tree/develop
I am using Swift4 and Xcode9.
I create my collectionView cells by using the delegate method below;
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "mediaItemCell", for: indexPath) as! MediaItemCollectionViewCell
cell.mediaItemCellImageView.image = mediaPlayer?.item(at: indexPath.row)?.image
return cell
}
Then, I want to replace the image of selected cell with a "stop" image. To achieve this, I have tried to use didSelectItemAt method;
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if (mediaPlayer?.isPlaying == true) {
// stop the player
mediaPlayer?.stopPlayingMedia()
} else {
// change the image and start playing
let cell = collectionView.cellForItem(at: indexPath) as! MediaItemCollectionViewCell // CRASH
cell.mediaItemCellImageView.image = UIImage(named: "stop.png")
...
...
}
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
// restore the original image
let cell = collectionView.cellForItem(at: indexPath) as! MediaItemCollectionViewCell
cell.mediaItemCellImageView.image = mediaPlayer?.item(at: indexPath.row)?.image
// stop playing
mediaPlayer?.stopPlayingMedia()
}
Now, when I select the cell which is already selected (hence the original image has already been replaced with "stop.png") the code above works; i.e. the original image is restored, which is done by stopPlayingMedia() method.
When I select a cell different than the currently selected one, the App crashes. I tried to move the didSelectItemAt call out of the delegate method, but it did not work.
Surprisingly, the logical check if collectionView.cellForItem(at: indexPath) is MediaItemCollectionViewCell succeeds when I select the currently selected cell, and fails when I select another cell.
I want to change the image of the cell, hence need to cast the variable type but it fails. Why does to cast fail when I select a different cell than the currently selected one?
Thanks
Edit:
I use collectionView.reloadData() to restore all the images to originals (I mentioned this in the OP - when stopPlayingMedia() is invoked). It appears that, if I add a private var index:IndexItem? to my ViewController class and update its value within didSelectItemAt (to save the last selected cell) and use the code below, the code does not crash
extension ViewController:MediaPlayerControllerDelegate {
// this delegate method is invoked when stopPlayingMedia() is called
func mediaPlayerControllerDidFinishPlaying() {
// restore the UI
// collectionView.reloadData() -> this causes the crash, instead, I only restore one cell
let cell = collectionView.cellForItem(at: index!) as! MediaItemCollectionViewCell
cell.mediaItemCellImageView.image = mediaPlayer?.item(at: (index?.row)!)?.image
timeLabel.text = "00:00"
progressBar.progress = 0.0
}
}
I tried the following to create cell and changing the image inside cell on selection. Not crashing at all. Please check the implementation, It might help you.
import UIKit
class ViewController: UIViewController {
private var isPlayingModel = [false, false, false, false, false] // initially all are stop, not playing
#IBOutlet weak var collectionView: UICollectionView! {
didSet{
collectionView.delegate = self
collectionView.dataSource = self
}
}
}
extension ViewController: UICollectionViewDataSource {
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return isPlayingModel.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "mediaItemCell", for: indexPath) as! MediaItemCollectionViewCell
cell.imageVw.image = isPlayingModel[indexPath.row] ? #imageLiteral(resourceName: "start") : #imageLiteral(resourceName: "stop")
return cell
}
}
extension ViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
isPlayingModel[indexPath.row] = !isPlayingModel[indexPath.row]
let cell = collectionView.cellForItem(at: indexPath) as! MediaItemCollectionViewCell
cell.imageVw.image = isPlayingModel[indexPath.row] ? #imageLiteral(resourceName: "start") : #imageLiteral(resourceName: "stop")
}
}
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.size.width, height: 60)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 4
}
}
class MediaItemCollectionViewCell: UICollectionViewCell {
#IBOutlet weak var imageVw: UIImageView!
}
Check the implementation here.
You are not passing indexPath correctly to load a cell, that's why it is crashing.Edit your didSelectItemAt: method as follows:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let selectedCell = IndexPath(item: indexPath.item, section: indexPath.section)
let cell = collectionView.cellForItem(at: selectedCell) as! ACollectionViewCell
cell.imgView.image = UIImage(named: "3.jpg")
}
Collection view indexPath has element item, and not row
Try this and see: (let me know what does it print)
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
// restore the original image
if let cell = collectionView.cellForItem(at: indexPath) as? MediaItemCollectionViewCell {
if let cellImage = mediaPlayer?.item(at: indexPath.item)?.image { // Collection view indexPath has element `item`, and not `row`
cell.mediaItemCellImageView.image = cellImage
} else {
print("cellImage not found at indexPath - \(indexPath)")
}
} else {
print("collection view cell `MediaItemCollectionViewCell` not found at indexPath -\(indexPath) ")
}
// stop playing
mediaPlayer?.stopPlayingMedia()
}