使用Swift 3为iOS应用创建自定义单元格

Question

First of all, I'm going insane trying to create a custom cell in iOS. Following dozens of other question answers, I don't seem to be getting the same result and I can't find out why. My use case: create a custom cell used in a table view, simple.

I have a table view sitting inside a UIView, with a single cell with a single label:

I gave my cell an identifier:

I link a custom class to the cell in the storyboard:

I link the label in the cell to an outlet on my custom class:

Here is the code from my view controller:

    class LoggedInViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
        @IBOutlet weak var tmImage: UIImageView!
        @IBOutlet weak var tmNameLabel: UILabel!
        @IBOutlet weak var tmMeetingLabel: UILabel!
        @IBOutlet weak var mainLabel: UILabel!
        @IBOutlet weak var attendeesTableView: UITableView!

        //Test table view details
        let names: [String] = ["Bobby", "Mark", "Waldo"]

        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view, typically from a nib

            //Setup table and cells
            attendeesTableView.delegate = self
            attendeesTableView.dataSource = self
            self.attendeesTableView.register(LoggedInTableViewCell.self, forCellReuseIdentifier: "attendeeCell")
        }

        func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            return self.names.count
        }

        func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
            let cell: LoggedInTableViewCell = self.attendeesTableView.dequeueReusableCell(withIdentifier: "attendeeCell", for: indexPath) as! LoggedInTableViewCell
            cell.cellNameLabel?.text = self.names[indexPath.row]
            return cell
        }
    }

And when this is ran, it returns nothing and the cell being returned from the method above is nil when printing:

Can anyone point me in the right direction?

Thanks!

Answer 1

You do not need to call the register(_:forCellReuseIdentifier:) instance method on your attendeesTableView . Removing this line should fix the cells not displaying.

The reason for this is you created the cell in the storyboard itself. Alternatively, if you designed it in a nib you would need to register it.

Matt Neuberg has an excellent and detailed explanation on designing a custom cell using the storyboard in his book titled "Programming iOS 10, Seventh Edition".

Here is a quote from his book regarding why you should not register if you are using the storyboard:

In your table view controller code, make sure you do not call register(_:for- CellReuseIdentifier:). If you do call it, you will be telling the runtime not to get the cell from the storyboard. (Neuberg, 2016, p. 469)

Neuberg, M. (2016). Programming iOS 10 7th Edition. California: O'Reilly Media