Isuru Isuru - 6 months ago 33
iOS Question

Custom UITableViewCell from nib in Swift

I'm trying to create a custom table view cell from a nib. I'm referring to this article here. I'm facing two issues.

I created a .xib file with a UITableViewCell object dragged on to it. I created a subclass of

UITableViewCell
and set it as the cell's class and Cell as the reusable identifier.

import UIKit

class CustomOneCell: UITableViewCell {

@IBOutlet weak var middleLabel: UILabel!
@IBOutlet weak var leftLabel: UILabel!
@IBOutlet weak var rightLabel: UILabel!

required init(coder aDecoder: NSCoder!) {
super.init(coder: aDecoder)
}

override init(style: UITableViewCellStyle, reuseIdentifier: String!) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
}

override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}

override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)

// Configure the view for the selected state
}

}


In the UITableViewController I have this code,

import UIKit

class ViewController: UITableViewController, UITableViewDataSource, UITableViewDelegate {

var items = ["Item 1", "Item2", "Item3", "Item4"]

override func viewDidLoad() {
super.viewDidLoad()
}

// MARK: - UITableViewDataSource
override func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
return items.count
}

override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
let identifier = "Cell"
var cell: CustomOneCell! = tableView.dequeueReusableCellWithIdentifier(identifier) as? CustomOneCell
if cell == nil {
tableView.registerNib(UINib(nibName: "CustomCellOne", bundle: nil), forCellReuseIdentifier: identifier)
cell = tableView.dequeueReusableCellWithIdentifier(identifier) as? CustomOneCell
}

return cell
}
}


This code complies with no errors but when I run it in the simulator, it looks like this.

enter image description here

In the UITableViewController in the storyboard I haven't done anything to the cell. Blank identifier and no subclass. I tried adding the Cell identifier to the prototype cell and ran it again but I get the same result.

Another error I faced is, when I tried to implement the following method in the UITableViewController.

override func tableView(tableView: UITableView!, willDisplayCell cell: CustomOneCell!, forRowAtIndexPath indexPath: NSIndexPath!) {

cell.middleLabel.text = items[indexPath.row]
cell.leftLabel.text = items[indexPath.row]
cell.rightLabel.text = items[indexPath.row]
}


As shown in the article I mentioned I changed the
cell
parameter's type form
UITableViewCell
to
CustomOneCell
which is my subclass of UITableViewCell. But I get the following error,

Overriding method with selector 'tableView:willDisplayCell:forRowAtIndexPath:' has incompatible type '(UITableView!, CustomOneCell!, NSIndexPath!) -> ()'

Anyone have any idea how to resolve these errors? These seemed to work fine in Objective-C.

Thank you.

EDIT: I just noticed if I change the simulator's orientation to landscape and turn it back to portrait, the cells appear! I still couldn't figure out what's going on. I uploaded an Xcode project here demonstrating the problem if you have time for a quick look.

Answer

You should try the following code for your project (updated for Swift 2):

CustomOneCell.swift

import UIKit

class CustomOneCell: UITableViewCell {

    // Link those IBOutlets with the UILabels in your .XIB file
    @IBOutlet weak var middleLabel: UILabel!
    @IBOutlet weak var leftLabel: UILabel!
    @IBOutlet weak var rightLabel: UILabel!

}

TableViewController.swift

import UIKit

class TableViewController: UITableViewController {

    let items = ["Item 1", "Item2", "Item3", "Item4"]

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.registerNib(UINib(nibName: "CustomOneCell", bundle: nil), forCellReuseIdentifier: "CustomCellOne")
    }

    // MARK: - UITableViewDataSource

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

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

        cell.middleLabel.text = items[indexPath.row]
        cell.leftLabel.text = items[indexPath.row]
        cell.rightLabel.text = items[indexPath.row]

        return cell
    }

}

The image below shows a set of constraints that work with the provided code without any constraints ambiguity message from Xcode.

enter image description here