使用#selector 传递参数
Passing parameters with #selector
我是 Swift 的初学者,我正在尝试通过 NotificationCenter 启动一个功能。 'ViewController.swift' 中的观察者调用函数 reload
:
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)
}
... 其参数为 class Ítem
:
class Item: NSObject {
let name: String
let iconName: String
init(name: String, iconName: String) {
self.name = name
self.iconName = iconName
}
}
通知发布自"menu.swift":
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' 中对象 items[indexPath.row]
的值赋给 'ViewController.swift' 中函数 reload
的参数?
如果你想在 类 周围传递一个注册到 NotificationCenter
的对象,你应该把它放入传递给观察者函数的通知对象的 .userInfo
字典中:
NotificationCenter.default.addObserver(self, selector: #selector(reload), 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)
}
}
我是 Swift 的初学者,我正在尝试通过 NotificationCenter 启动一个功能。 'ViewController.swift' 中的观察者调用函数 reload
:
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)
}
... 其参数为 class Ítem
:
class Item: NSObject {
let name: String
let iconName: String
init(name: String, iconName: String) {
self.name = name
self.iconName = iconName
}
}
通知发布自"menu.swift":
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' 中对象 items[indexPath.row]
的值赋给 'ViewController.swift' 中函数 reload
的参数?
如果你想在 类 周围传递一个注册到 NotificationCenter
的对象,你应该把它放入传递给观察者函数的通知对象的 .userInfo
字典中:
NotificationCenter.default.addObserver(self, selector: #selector(reload), 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)
}
}