IBoutlet is nil in my custom table cell? - ios

Question

//custom cell in one swift file
import UIKit
class CardTableViewCell: UITableViewCell {
#IBOutlet weak var elapsedTime: UILabel!
#IBOutlet weak var todo: UILabel!
#IBOutlet weak var startAndStop: UIView!
#IBOutlet weak var progress: UIView!
#IBOutlet weak var cardView: UIView!
}
//custom Table view controller in another swift file
import UIKit
class CardFeedTableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CardTableViewCell.self, forCellReuseIdentifier: "cardCell")
tableView.delegate = self
tableView.dataSource = self
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: CardTableViewCell = self.tableView.dequeueReusableCell(withIdentifier: "cardCell", for: indexPath) as! CardTableViewCell
cell.todo.text = "study"
return cell
}
running the app triggers a error
storyboard
I don't know why all the properties in the my table cell is nil, when I run the app.

Answer 1

There are two variants to register, but both take a parameter called
forCellReuseIdentifier, which is a string that lets you register
different kinds of table view cells. For example, you might have a
reuse identifier "DefaultCell", another one called "Heading cell",
another one "CellWithTextField", and so on. Re-using different cells
this way helps save system resources.
If you want to use register() with a Swift class, you provide a table
view cell class as its first parameter. This is useful if your cell is
defined entirely in code. As an example, this uses the default
UITableViewCell class:
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "DefaultCell")
You can then dequeue that cell like this:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "DefaultCell")!
return cell
}
The other option is to use register() with an Interface Builder nib
file. Nibs contain the class name to use along with their design, so
this method is more common. Here's an example
tableView.register(UINib(nibName: "yourNib", bundle: nil), forCellReuseIdentifier: "CellFromNib")
But if you're using storyboards you will find it easier to create
prototype cells and give them a reuse identifier directly inside
Interface Builder.So no need to register programmatically.
Remove this line form viewDidLoad
tableView.register(CardTableViewCell.self, forCellReuseIdentifier: "cardCell).