I'm new to learning swift. When I run my code I expect to see an email address in a cell with a Detail disclosure to the right of it. Instead, I see blank cells.

Main.storyboard

AddressBookTableViewController.swift

    import UIKit

        class AddressBookTableViewController: UITableViewController {
        let dataSource = ContactEmailDataSource()
        override func viewDidLoad() {
        super.viewDidLoad()

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Uncomment the following line to display an Edit button in the navigation bar 
        for this view controller.
        // self.navigationItem.rightBarButtonItem = self.editButtonItem
        }

        // MARK: - Table view data source

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

    
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return dataSource.countOfEmails()
    }

    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ContactCell", for: indexPath)

        let cellContact = dataSource.emailAtIndex(index: indexPath.row)
        cell.textLabel?.text = cellContact.emailAddress
        
        return cell
    }
    

    /*
    // Override to support conditional editing of the table view.
    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        // Return false if you do not want the specified item to be editable.
        return true
    }
    */

    /*
    // Override to support editing the table view.
    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            // Delete the row from the data source
            tableView.deleteRows(at: [indexPath], with: .fade)
        } else if editingStyle == .insert {
            // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
        }
    }
    */

    /*
    // Override to support rearranging the table view.
    override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) {

    }
    */

    /*
    // Override to support conditional rearranging of the table view.
    override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {
        // Return false if you do not want the item to be re-orderable.
        return true
    }
    */

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */

}

ContactEmail.swift

    import UIKit

class ContactEmail: NSObject
{
    var emailAddress: String
    
    override init ()
    {
        emailAddress = "[email protected]"
        super.init()
    }
    
    init(emailAddress email: String)    
    {
        emailAddress = email
        super.init()
    }
}

ContactEmailDataSource.swift

    import UIKit

class ContactEmailDataSource: NSObject
{
    let emailAddresses = NSMutableArray()
    
    override init()
    {
        super.init()
        loadEmailAddresses()
    }
    func loadEmailAddresses()
    {
        let sample1 = ContactEmail()
        emailAddresses.add(sample1)
        let sample2 = ContactEmail(emailAddress: "[email protected]")
        addEmail(contact: sample2)
    }
    func addEmail(contact c: ContactEmail)
    {
        emailAddresses.add(c)
    }
    func countOfEmails() -> Int
    {
        return emailAddresses.count
    }
    func emailAtIndex(index i: Int) -> ContactEmail
    {
        return emailAddresses.object(at: i) as! ContactEmail
    }
}

Let me know if more screenshots or more information is needed. Thanks.

CodePudding user response：

did you register the cell to the tableview? take a look at this link

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

CodePudding user response：

Replace your controller class by this. In your code you didn't close the viewDidLoad() method by ending } .You did putted all tableview Delegate and Datasource code into the viewDidLoad() method. That's why tableview Delegate and Datasource methods are not executed.

class AddressBookTableViewController: UITableViewController {
    let dataSource = ContactEmailDataSource()
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false
        
        // Uncomment the following line to display an Edit button in the navigation bar
        
        // MARK: - Table view data source
    }
    
    override func numberOfSections(in tableView: UITableView) -> Int
    {
        return 1
    }
    
    
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return dataSource.countOfEmails()
    }
    
    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ContactCell", for: indexPath)
        
        let cellContact = dataSource.emailAtIndex(index: indexPath.row)
        cell.textLabel?.text = cellContact.emailAddress
        
        return cell
    }
    
    
}