How to add addTarget for Button in UICollectionView? - ios

Question

I'm a newbie, I have the following problem. There is a screen like this picture. I use UICollectionViewCell for header and I can't addTarget for the blue button in this.
I can’t manage. Could you help me?
class UserProfileVC: UICollectionViewController, UICollectionViewDelegateFlowLayout,UserProfileHeaderDelegate{
var currentUser: User?
var userToLoadFromSearchVC: User?
override func viewDidLoad() {
super.viewDidLoad()
// Register cell classes
self.collectionView!.register(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)
// resgiter header class before use
self.collectionView!.register(UserProfileHeader.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader , withReuseIdentifier: headerIdentifier)
// back ground color
self.collectionView?.backgroundColor = .white
//fetch user data
if userToLoadFromSearchVC == nil{
fetchCurrentUserData()
}
}
override func numberOfSections(in collectionView: UICollectionView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of items
return 0
}
// config size for header
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: view.frame.width, height: 200)
}
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
// Declare header
let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerIdentifier, for: indexPath) as! UserProfileHeader
// set delegate
header.delegate = self
if let user = self.currentUser {
header.user = user
} else if let userToLoadFromSearchVC = self.userToLoadFromSearchVC {
header.user = userToLoadFromSearchVC
self.navigationItem.title = userToLoadFromSearchVC.username
}
// Return header
return header
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
}
This is my code in header file.
class UserProfileHeader: UICollectionViewCell {
var delegate: UserProfileHeaderDelegate?
var user: User? {
didSet {
configuredEditProfileFollowButton()
setUserStats(for: user)
let fullName = user?.name
nameLabel.text = fullName
guard let profileImageUrl = user?.profileImage else {return}
profileImageView.loadImage(with:profileImageUrl)
}
}
let profileImageView : UIImageView = {
let iv = UIImageView()
iv.contentMode = .scaleAspectFill
iv.clipsToBounds = true
iv.backgroundColor = .lightGray
return iv
}()
let nameLabel: UILabel = {
let label = UILabel()
label.font = UIFont.boldSystemFont(ofSize: 12)
return label
}()
let postLabel: UILabel = {
let label = UILabel()
label.numberOfLines = 0
label.textAlignment = .center
let attributedText = NSMutableAttributedString(string:"5\n",attributes:[NSAttributedString.Key.font:UIFont.boldSystemFont(ofSize: 14)])
attributedText.append(NSAttributedString(string:"posts",attributes: [NSAttributedString.Key.font:UIFont.boldSystemFont(ofSize: 14), NSAttributedString.Key.foregroundColor:UIColor.lightGray]))
label.attributedText = attributedText
return label
}()
let followersLabel: UILabel = {
let label = UILabel()
label.numberOfLines = 0
label.textAlignment = .center
return label
}()
let followingLabel: UILabel = {
let label = UILabel()
label.numberOfLines = 0
label.textAlignment = .center
let attributedText = NSMutableAttributedString(string:"5\n",attributes:[NSAttributedString.Key.font:UIFont.boldSystemFont(ofSize: 14)])
attributedText.append(NSAttributedString(string:"following",attributes:[NSAttributedString.Key.font:UIFont.boldSystemFont(ofSize: 14), NSAttributedString.Key.foregroundColor:UIColor.lightGray]))
label.attributedText = attributedText
return label
}()
let editProfileFollowButton : UIButton = {
let button = UIButton(type: .system)
button.setTitle("Loading", for: .normal)
button.layer.cornerRadius = 5
button.layer.borderColor = UIColor.lightGray.cgColor
button.layer.borderWidth = 0.5
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
button.setTitleColor(.black, for: .normal)
button.addTarget(self, action: #selector(handleEditProfileFollow), for: .touchUpOutside)
return button
}()
let gridButton : UIButton = {
let button = UIButton(type: .system)
button.setImage(UIImage(named: "grid"), for: .normal)
return button
}()
let listButton : UIButton = {
let button = UIButton(type: .system)
button.setImage(UIImage(named:"list"), for: .normal)
button.tintColor = UIColor(white: 0, alpha: 0.2)
return button
}()
let bookmarkButton : UIButton = {
let button = UIButton(type: .system)
button.setImage(UIImage(named:"ribbon"), for: .normal)
button.tintColor = UIColor(white: 0, alpha: 0.2)
button.addTarget(self, action: #selector(testFunc(_:)), for: UIControl.Event.touchUpInside)
return button
}()
#objc func testFunc(_ sender : UIButton){
print("Pressed ")
}
#objc func handleFollowersTapped() {
delegate?.handleFollowersTapped(for: self)
}
#objc func handleFollowingTapped() {
delegate?.handleFollowingTapped(for: self)
}
#objc func handleEditProfileFollow() {
guard let user = self.user else {return}
if editProfileFollowButton.titleLabel?.text == "Edit Profile"{
print("Handler edit profile ")
}
else{
if editProfileFollowButton.titleLabel?.text == "Follow"{
editProfileFollowButton.setTitle("Following", for: .normal)
user.follow()
}else{
editProfileFollowButton.setTitle("Follow", for: .normal)
user.unfollow()
}
}
}

Answer 1

This is because you are creating the button target before the UserProfileHeader initialized. So you need to create the button using lazy var (lazily).
private lazy var button: UIButton = {
let button = UIButton()
button.setTitle("Button", for: .normal)
button.addTarget(self, action: #selector(handleButtonTapped), for: .touchUpInside)
return button
}()
#objc private func handleButtonTapped() {
print("Button tapped")
}

Answer 2

Try this, i think this will help you.
class customCell: UICollectionViewCell {
#IBOutlet weak var btn: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
}
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: customCell = collectionView.dequeueReusableCell(withReuseIdentifier: "customCell", for: indexPath) as! customCell
cell.btn.tag = indexPath.row
cell.btn.addTarget(self, action: #selector(self.btnpressed(sender:)), for: .touchUpInside)
return cell
}
#objc func btnpressed(sender: UIButton!) {
print(sender.tag)
}
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: customCell, for: indexPath) as! customCell
view.pagePluginButtonAction = {
self.TapedBtn()
}
return view
}
func TapedBtn(){
print("click")
}

Answer 3

You need to add the target in 'viewForSupplementaryElementOfKind' where you set up your header. See example below, just after you set the header delegate.
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
// Declare header
let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerIdentifier, for: indexPath) as! UserProfileHeader
// set delegate
header.delegate = self
// Add the target here
header.yourButton.addTarget(self, action: #selector(handleYourButton), for: .touchUpInside)
if let user = self.currentUser {
header.user = user
} else if let userToLoadFromSearchVC = self.userToLoadFromSearchVC {
header.user = userToLoadFromSearchVC
self.navigationItem.title = userToLoadFromSearchVC.username
}
// Return header
return header
}