ios swift tableview 不显示自定义单元格

Question

I am trying to create a table view with custom cells from Storyboard layout in an iOS app.

But for some reason the table cells are not being shown. When I tried to set debug breakpoints I found that the debugger is reaching this function

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int

but it never reaches this function -

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell

Here is my viewcontroller code -

extension NavigationViewController: UITableViewDataSource, UITableViewDelegate, SideMenuControllerDelegate {

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

    public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "SideMenuTableItem", for: indexPath as IndexPath) as! SideMenuTableItem
        cell.setItemData(items[indexPath.row])
        return cell
    }

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

    func setupTableViews() {
        menuTable.register(SideMenuTableItem.self, forCellReuseIdentifier: "SideMenuTableItem")

    }
}

class SideMenuTableItem: UITableViewCell {

    @IBOutlet weak var menuImage: UIImageView!
    @IBOutlet weak var menuLabel: UILabel!

    var data: MenuItem?

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

    func setItemData(_ item: MenuItem) {
        data = item
        menuLabel.text = data?.title
        if data?.icon_res != nil {
            menuImage.image = UIImage(named: (data?.icon_res)!)
        }
    }

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

I have checked in the storyboard that I have set the reusable identifier to the table prototype cell and also connected the datasource and the delegate properties to the tableview

and I am calling the setupTableViews() method inside my viewDidLoad() function after creating the items array But still I am not able to get the cells to appear in my view at all. Can anyone suggest what am I missing here or what's wrong with my code, or how can I further debug this issue

import UIKit
import SideMenuSwift

class NavigationViewController: UIViewController {

    @IBOutlet weak var navigationContainer: UIView!
    @IBOutlet weak var emailButton: UIButton!
    @IBOutlet weak var phoneButton: UIButton!
    @IBOutlet weak var userAvatar: UIImageView!
    @IBOutlet weak var userProfile: UIButton!
    @IBOutlet weak var userName: UILabel!
    @IBOutlet weak var menuTable: UITableView!

    var service: AuthenticationService!
    var cdc: CoreDataController!
    var items: [MenuItem] = []
    var currentUser: User?

    override func viewDidLoad() {
        super.viewDidLoad()
        setupSidebar()
        initSidebarData()
        setupUserHeader()
        setupTableViews()
    }

    func setupUserHeader() {
        if currentUser != nil {
            if currentUser?.name != nil {
                userName.text = currentUser?.name
            } else if currentUser?.role != nil {
                userName.text = "urTutors " + (currentUser?.role ?? "")
            }
            if currentUser?.avatarUrl != nil {
                userAvatar.downloaded(from: (currentUser?.avatarUrl)!)
            }
        }
    }

    func initSidebarData() {
        service = AuthenticationServiceProvider()
        cdc = CoreDataController()
        items = cdc.getNavigationData()
        currentUser = cdc.getUserData()
    }

    func setupSidebar() {
        self.view.backgroundColor = UIColor.hexColor("#fff")
        navigationContainer.backgroundColor = UIColor.hexColor("#2a2a2a")
        SideMenuController.preferences.basic.statusBarBehavior = .hideOnMenu
        SideMenuController.preferences.basic.position = .above
        SideMenuController.preferences.basic.direction = .left
        SideMenuController.preferences.basic.enablePanGesture = true
        SideMenuController.preferences.basic.menuWidth = 275
        sideMenuController?.delegate = self
    }

    static func createViewController() -> NavigationViewController {
        let sb = UIStoryboard(name: "StudentHomeModuleStoryboard", bundle: nil)
        let vc = sb.instantiateViewController(withIdentifier: "NavigationViewController")
        return vc as! NavigationViewController
    }
}

--UPDATE--

updated setupTableLayout function -

func setupTableViews() {
        let bundle = Bundle(for: type(of: self))
        let cellNib = UINib(nibName: "SideMenuTableItem", bundle: bundle)
        menuTable.register(cellNib, forCellReuseIdentifier: "SideMenuTableItem")
        menuTable.register(SideMenuTableItem.self, forCellReuseIdentifier: "SideMenuTableItem")
        menuTable.reloadData()
    }

Answer 1

After breaking into chat on this, we found that there were two issues.

The first issue was the missing reloadData call mentioned above. That was causing cellForRow to not be called. Adding reloadData corrected that issue, but then the custom cell class's outlets were nil, causing a crash in setItemData .

The second issue was that register(_:forCellReuseIdentifier:) was being called in code, but the custom cell was already setup as part of the Interface Builder UITableView declaration. Calling register again on the custom class re-registered the reuseIdentifier , disconnecting the outlets set up in the storyboard.

Removing the register call and adding reloadData solved all issues.

Answer 2

You are never calling setupTableViews() . You'r code should look like this:

class NavigationViewController: UIViewController, SideMenuControllerDelegate {

override func viewDidLoad() {
        super.viewDidLoad()

        setupTableViews()
    }

func setupTableViews() {
menuTable.reloadData()
    }
}

extension NavigationViewController: UITableViewDataSource, UITableViewDelegate {

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

    public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "SideMenuTableItem", for: indexPath as IndexPath) as! SideMenuTableItem
        cell.setItemData(items[indexPath.row])
        return cell
    }

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

You are never calling the function, nor calling viewDidLoad. This should help. Also, where is the rest of your view controller code (is this all of it? It should not be!).

You don't need to register your cell because you requested it and make sure you reloadData().

Hope this helps!