我想在一个单独的类中实现数据源。我的实现似乎在这里有效
这是我的UITableViewController
class MasterViewController: UITableViewController {
@IBOutlet weak var itemsTableView: UITableView!
let loginManager = LoginManager.shared
let preferences = UserDefaultsManager.shared
let appDelegate = UIApplication.shared.delegate
var delegate: PreferencesDelegate?
let apiClient = ApiClient.shared
var timer:Timer?
var count: Int = 10
var items:[Item]? {
didSet {
let dataSource = ItemDataSource(items: items!)
tableView.dataSource = dataSource
tableView.reloadData()
//itemsTableView.dataSource = self
//itemsTableView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
configureView()
}
func configureView() {
self.navigationController?.navigationBar.topItem?.title = "You are logged in"
apiClient.getData { (items) in
DispatchQueue.main.async {
self.items = items
self.tableView.reloadData()
}
}
DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
//seconds delay before starting timer
self.runTimer()
}
}
func runTimer() {
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(MasterViewController.updateTimer)), userInfo: nil, repeats: true)
}
@objc func updateTimer() {
if count > 0 {
count -= 1
self.navigationController?.navigationBar.topItem?.title = "session will expire in (count) seconds"
}
if count == 0 {
preferences.clear()
pushToLoginVC()
timer?.invalidate()
}
}
func pushToLoginVC() {
let navigationCoordinator = NavigationCoordinator(window: appDelegate!.window!!)
navigationCoordinator.setRoot(id: "LoginVC")
delegate?.getCurrentUser()
}
}
这是数据源类
class ItemDataSource: NSObject, UITableViewDataSource {
private var items: [Item]
init(items: [Item]) {
self.items = items
super.init()
}
// MARK: - Data Source
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
print("configure cell triggered")
let itemCell = tableView.dequeueReusableCell(withIdentifier: "itemCell", for: indexPath) as! ItemViewCell
let item = items[indexPath.row]
let cellViewModel = ItemViewModel(item: item)
itemCell.configure(viewModel: cellViewModel)
return itemCell
}
// MARK: - Helper
func item(at indexPath: IndexPath) -> Item {
return items[indexPath.row]
}
}
单元格标识符设置为"项目单元格"自定义类也设置为"项目视图单元格">
以分配数据源。我用项目初始化数据源我放了断点,我注意到 **cellForRowAt indexPath 从未被调用。
数据是从 JSON 文件中读取的。 数组不为空。 它已经过测试。tableView.dataSource 不是 nil。该应用程序不会崩溃主要问题是cellForRowAt indexPath。我似乎想不通。我可以将所有数据源方法保留在同一个 MasterViewController 中,尽管我真的很想保留数据源方法以获得更好的代码质量,主要是在视图控制器变大时
知道有人吗?
更新我的问题:
根据我收到的答案,我添加了var dataSource:ItemDataSource作为强参考。
如果数据源是本地的,则数据源是弱的,不会被保留
class MasterViewController: UITableViewController {
@IBOutlet weak var itemsTableView: UITableView!
let loginManager = LoginManager.shared
let preferences = UserDefaultsManager.shared
let appDelegate = UIApplication.shared.delegate
var delegate: PreferencesDelegate?
let apiClient = ApiClient.shared
var timer:Timer?
var count: Int = 10
**var dataSource:ItemDataSource?**
var items:[Item]? {
didSet {
**dataSource = ItemDataSource(items: items!)**
tableView.dataSource = dataSource
tableView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
configureView()
}
func configureView() {
self.navigationController?.navigationBar.topItem?.title = "You are logged in"
apiClient.getData { (items) in
DispatchQueue.main.async {
self.items = items
}
}
DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
//seconds delay before starting timer
self.runTimer()
}
}
func runTimer() {
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(MasterViewController.updateTimer)), userInfo: nil, repeats: true)
}
@objc func updateTimer() {
if count > 0 {
count -= 1
self.navigationController?.navigationBar.topItem?.title = "session will expire in (count) seconds"
}
if count == 0 {
preferences.clear()
pushToLoginVC()
timer?.invalidate()
}
}
func pushToLoginVC() {
let navigationCoordinator = NavigationCoordinator(window: appDelegate!.window!!)
navigationCoordinator.setRoot(id: "LoginVC")
delegate?.getCurrentUser()
}
}