swift – 使用#selector传递参数
发布时间:2020-12-14 04:38:18 所属栏目:百科 来源:网络整理
导读:我是 Swift的初学者,我正试图通过NotificationCenter启动一个功能. ‘ViewController.swift’中的观察者调用函数重载: override func viewDidLoad() { super.viewDidLoad() NotificationCenter.default.addObserver(self,selector: #selector(reload),name:
我是
Swift的初学者,我正试图通过NotificationCenter启动一个功能. ‘ViewController.swift’中的观察者调用函数重载:
override func viewDidLoad() { super.viewDidLoad() NotificationCenter.default.addObserver(self,selector: #selector(reload),name: NSNotification.Name(rawValue: "reload"),object: nil) } func reload(target: Item) { print(target.name) print(target.iconName) } …具有类ítem的参数: class Item: NSObject { let name: String let iconName: String init(name: String,iconName: String) { self.name = name self.iconName = iconName } } 通知从“menu.swift”发布: class menu: UIView,UITableViewDelegate,UITableViewDataSource { let items: [Item] = { return [Item(name: "Johnny",iconName: "A"),Item(name: "Alexis",iconName: "B"),Item(name: "Steven",iconName: "C")] }() ... func tableView(_ tableView: UITableView,didSelectRowAt indexPath: NotificationCenter.default.post(name: NSNotification.Name(rawValue: "reload"),object: items[indexPath.row]) } 如何将’menu.swift’中的对象项[indexPath.row]的值分配给’ViewController.swift’中函数reload的参数? 解决方法
如果要在注册到NotificationCenter的类周围传递对象,则应将其放入传递给observer函数的通知对象的
.userInfo 字典中:
NotificationCenter.default.addObserver(self,name: Notification(name: "reload"),object: nil) – let userInfo = ["item": items[indexPath.row]] NotificationCenter.default.post(name: "reload",object: nil,userInfo: userInfo) – func reload(_ notification: Notification) { if let target = notification.userInfo?["item"] as? Item { print(target.name) print(target.iconName) } } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |