How to show check tick mark in Collection view (images) - ios

Question

In Table view we can put checkmark easily on cells.
But in Collection View how can we put check mark, when we select a cell (image)?
I just took a image view inside the cell and image view and put a tick mark image. My code is below.
But it's not working.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath)
{
// handle tap events
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! customCollectionViewCell
if(cell.checkMarkImage.hidden == true)
{
print("Hidden")
cell.checkMarkImage.hidden = false
}
else
{
cell.checkMarkImage.hidden = true
print("No Hidden")
}
}

Answer 1

//Delegate Method cellForItemAtIndexPath
func collectionView(collectionView: UICollectionView,
cellForItemAtIndexPath indexPath: NSIndexPath) ->
UICollectionViewCell
{
//Get a reference to our storyboard cell
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(
"pickSomecell",
forIndexPath: indexPath) as! pickSomeGridViewController
//Show Images in grid view
cell.cellImage.image = self.arrAllOriginalImages[indexPath.row]
as? UIImage
//Check Mark toggle.
cell.toggleSelected()
//return cell.
return cell
}
And in pickSomeGridViewController show checkMark image selected or not.
class pickSomeGridViewController: UICollectionViewCell{
//Outlet of cell image.
#IBOutlet var cellImage: UIImageView!
//Outlet of checkMark image.
#IBOutlet var cellCheckMarkImage: UIImageView!
//Function for select and deselect checkmark.
func toggleSelected ()
{
//If image is selected.
if (selected)
{
//Show check mark image.
self.cellCheckMarkImage.hidden = false
}
else
{
//Hide check mark image.
self.cellCheckMarkImage.hidden = true
}
}
}

Answer 2

I see two main problems with this code:
You use dequeueReusableCellWithReuseIdentifier method which obtains different cell from collection view cache, not the one on screen.
Use cellForItemAtIndexPath method of collection view instead.
You try to save cell's state (selected/not selected) in the cell itself. It's common mistake when working with UITableView/UICollectionView and this approach will not work. Instead, keep the state in some other place (in dictionary, for example) and restore it every time collection view calls your data source cellForItemAtIndexPath method.

Answer 3

var arrData = NSMutableArray()
// 1.Make a ModalClass.swift and NSArray with modal class objects like this
class CustomModal: NSObject {
//Declare bool variable for select and deselect login
var is_selected = Bool()
//you can declare other variable also
var id = Int32()
}
// 2. custom array with modal objects
override func viewDidLoad() {
super.viewDidLoad()
let arrTemp = NSArray()
arrTemp = [1,2,3,4,5,6,7,8,9,10]
for i in 0 ..< arrTemp.count{
let eventModal = CustomModal()
eventModal.is_selected = false
eventModal.id = arrTemp[i]
arrData.add(eventModal)
}
tblView.reloadData()
}
// 2. Use collection view delegate method
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let modal = arrData[indexPath.row] as! CustomModal()
modal.is_selected = true
self.arrData.replaceObject(at: indexPath.row, with: modal)
tblView.reloadData()
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let modal = arrData[indexPath.row] as! CustomModal()
modal.is_selected = false
self.arrData.replaceObject(at: indexPath.row, with: modal)
tblView.reloadData()
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! YourCellClass
let modal = arrData[indexPath.row] as! CustomModal
if modal.is_selected == true{
cell.imgView.image = UIImage(named:"selected_image")
}else{
cell.imgView.image = UIImage(named:"deselected_image")
}
}

Answer 4

#Kishor, paintcode is the third party tool through which you can do that. I have provided the link too. since by default you don't have this facility, you should make your custom behavior to achiever this. Thanks.

Answer 5

Swift 4
In ViewController
// make a cell for each cell index path
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "YourCollectionViewCellID", for: indexPath as IndexPath) as! YourCollectionViewCell
cell.someImageView.image = imgArr[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("You selected cell #\(indexPath.item)!")
let cell = collectionView.cellForItem(at: indexPath) as? YourCollectionViewCell
cell?.isSelected = true
cell?.toggleSelected()
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as? YourCollectionViewCell
cell?.isSelected = false
cell?.toggleSelected()
}
In YourCollectionViewCell
class YourCollectionViewCell: UICollectionViewCell {
#IBOutlet weak var someImageView: UIImageView!
#IBOutlet weak var checkImageView: UIImageView!
//Function for select and deselect checkmark.
public func toggleSelected() {
if (isSelected == false) {
//Hide check mark image.
self.checkImageView.image = UIImage(named: "unCheckImage")
isSelected = true
}else{
//Show check mark image.
self.checkImageView.image = UIImage(named: "CheckImage")
isSelected = false
}
}
}
Hope enjoy!!

Answer 6

var selectedCellIndex:Int?
take variable if you want to show selected Item after reloadData() : which is previously selected CellItem. {inspired by above answer }
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ColorCollectionCell", for: indexPath) as! ColorCollectionCell
cell.isSelected = false
if selectedCellIndex == indexPath.item {
cell.checkMarkImgView.image = UIImage(named: "icn_checkMark")
}else {
cell.toggleSelected()
}
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as! ColorCollectionCell
cell.isSelected = true
selectedCellIndex = indexPath.item
cell.toggleSelected()
}
In CollectionViewCell u can use this method
class ColorCollectionCell: UICollectionViewCell {
#IBOutlet weak var cellimgView: UIImageView!
#IBOutlet weak var checkMarkImgView: UIImageView!
func toggleSelected() {
if (isSelected) {
self.checkMarkImgView.image = UIImage(named: "icn_checkMark")
}else{
self.checkMarkImgView.image = UIImage(named: "")
// here you can use uncheck img here i am not using any image for not selected.
}
}
}