unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

问题

I am fairly new to coding in general and really new to Xcode (Swift). I understand that I need to register a nib or a class but I don't understand 'where or how?'.

import UIKit

class NotesListViewController: UITableViewController {

    @IBOutlet weak var menuButton: UIBarButtonItem!

  override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self,
      selector: "preferredContentSizeChanged:",
      name: UIContentSizeCategoryDidChangeNotification,
      object: nil)

    // Side Menu

    if self.revealViewController() != nil {
        menuButton.target = self.revealViewController()
        menuButton.action = "revealToggle:"
        self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
    }

  }

  override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    // whenever this view controller appears, reload the table. This allows it to reflect any changes
    // made whilst editing notes
    tableView.reloadData()
  }

  func preferredContentSizeChanged(notification: NSNotification) {
    tableView.reloadData()
  }

  // #pragma mark - Table view data source

  override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
  }

  override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return notes.count
  }

  override func tableView(tableView: UITableView, cellForRowAtIndexPath   indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell

    let note = notes[indexPath.row]
    let font = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
    let textColor = UIColor(red: 0.175, green: 0.458, blue: 0.831, alpha: 1)
    let attributes = [
      NSForegroundColorAttributeName : textColor,
      NSFontAttributeName : font,
      NSTextEffectAttributeName : NSTextEffectLetterpressStyle
    ]
    let attributedString = NSAttributedString(string: note.title, attributes: attributes)

    cell.textLabel?.font = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)

    cell.textLabel?.attributedText = attributedString

    return cell
  }

  let label: UILabel = {
    let temporaryLabel = UILabel(frame: CGRect(x: 0, y: 0, width: Int.max, height: Int.max))
    temporaryLabel.text = "test"
    return temporaryLabel
    }()

  override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    label.font = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
    label.sizeToFit()
    return label.frame.height * 1.7
  }

  override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
      notes.removeAtIndex(indexPath.row)
      tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
    }
  }

  // #pragma mark - Navigation

  // In a storyboard-based application, you will often want to do a little preparation before navigation
  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if let editorVC = segue.destinationViewController as? NoteEditorViewController {

      if "CellSelected" == segue.identifier {
        if let path = tableView.indexPathForSelectedRow() {
          editorVC.note = notes[path.row]
        }
      } else if "AddNewNote" == segue.identifier {
        let note = Note(text: " ")
        editorVC.note = note
        notes.append(note)
      }
    }
  }

}

回答1:

Have you set the Table Cell identifier to "Cell" in your storyboard?

Or have you set the class for the UITableViewController to your class in that scene?

回答2:

You can register a class for your UITableViewCell like this:

With Swift 3+:

self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")

With Swift 2.2:

self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")

Make sure same identifier "cell" is also copied at your storyboard's UITableViewCell.

"self" is for getting the class use the class name followed by .self.

回答3:

This worked for me, May help you too :

Swift 4+ :

self.tableView.register(UITableViewCell.self, forCellWithReuseIdentifier: "cell")

Swift 3 :

self.tableView.register(UITableViewCell.classForKeyedArchiver(), forCellReuseIdentifier: "Cell")

Swift 2.2 :

self.tableView.registerClass(UITableViewCell.classForKeyedArchiver(), forCellReuseIdentifier: "Cell")

We have to Set Identifier property to Table View Cell as per below image,

回答4:

I had this issue today which was solved by selecting Product -> Clean. I was so confused since my code was proper. The problem started from using command-Z too many times :)

回答5:

y my case i solved this by named it in the "Identifier" property of Table View Cell:

Don't forgot: to declare in your Class: UITableViewDataSource

 let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as UITableViewCell

回答6:

Just drag a cell (as you did for TableViewController) and add in to it just by releasing the cell on TableViewController. Click on the cell and.Go to its attributes inspector and set its identifier as "Cell".Hope it works.

---

Don't forget you want Identifier on the Attributes Inspector.

(NOT the "Restoration ID" on the "Identity Inspector" !)

回答7:

One more reason for this issue to happen is an earlier problem. When showing a new ViewController, instantiating the target ViewController directly will of course not load the prototype cells from the StoryBoard. The correct solution should always be to instantiate the view controller through the story board like this:

storyboard?.instantiateViewController(withIdentifier: "some_identifier")

回答8:

In Swift 3.0, register a class for your UITableViewCell like this :

tableView.register(UINib(nibName: "YourCellXibName", bundle: nil), forCellReuseIdentifier: "Cell")

回答9:

My problem was I was registering table view cell inside dispatch queue asynchronously. If you have registered table view source and delegate reference in storyboard then dispatch queue would delay the registration of cell as name suggests it will happen asynchronously and your table view is looking for the cells.

DispatchQueue.main.async {
    self.tableView.register(CampaignTableViewCell.self, forCellReuseIdentifier: CampaignTableViewCell.identifier())
    self.tableView.reloadData()
}

Either you shouldn't use dispatch queue for registration OR do this:

DispatchQueue.main.async {
    self.tableView.dataSource = self
    self.tableView.delegate = self
    self.tableView.register(CampaignTableViewCell.self, forCellReuseIdentifier: CampaignTableViewCell.identifier())
    self.tableView.reloadData()
}

回答10:

I just met the same issue and see this post. For me it's because I forgot the set the identifier of cell, also as mentioned in other answers. What I want to say is that if you are using the storyboard to load custom cell we don't need to register the table view cell in code, which can cause other problems.

See this post for detail:

Custom table view cell: IBOutlet label is nil

回答11:

I had the same problem. This issue worked for me. In storyboard select your table view and change it from static cells into dynamic cells.

回答12:

If you defined your cell through the Interface Builder, by placing a cell inside your UICollectionView, or UITableView :

Make sure you binded the cell with an actual class you created, and very important, that you checked "Inherit module from target"

回答13:

It used to work on swift 3 and swift 4 but now its not working.

like

self.tableView.register(MyTestTableViewCell.self, forCellReuseIdentifier: "cell")

So I have tried the most of the solutions mentioned above in swift 5 but did not get any luck.

Finally I tried this solution and it worked for me.

override func viewDidLoad() 
{

    tableView.register(UINib.init(nibName: "MyTestTableViewCell", bundle: nil), forCellReuseIdentifier: "myTestTableViewCell")
}

回答14:

Just for those new to iOS buddies (like me) who decided to have multiple cells and in a different xib file, the solution is not to have identifier but to do this:

let cell = Bundle.main.loadNibNamed("newsDetails", owner: self, options: nil)?.first as! newsDetailsTableViewCell

here newsDetails is xib file name.

回答15:

Swift 5

you need to use UINib method to register cell in viewDidLoad

override func viewDidLoad() 
{
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    //register table view cell        
    tableView.register(UINib.init(nibName: "CustomTableViewCell", bundle: nil), forCellReuseIdentifier: "CustomTableViewCell")
}

回答16:

In the “Subclass of” field, select UITableViewController.

The class title changes to xxxxTableViewController. Leave that as is.

Make sure the “Also create XIB file” option is selected.

回答17:

static var identifier : String { return String(describing: self) }

static var nib : UINib {
    return UINib(nibName: identifier, bundle: nil)
}

回答18:

I ran into this message when UITableView in the IB was moved into another subview with Cmd-C - Cmd-V.

All identifiers, delegate methods, links in the IB etc. stay intact, but exception is raised at the runtime.

The only solution is to clear all inks, related to tableview in the IB (outlet, datasource, delegate) and make them again.

来源：https://stackoverflow.com/questions/29282447/unable-to-dequeue-a-cell-with-identifier-cell-must-register-a-nib-or-a-class-f