目标-C观察者-如何在Swift中使用

Question

我添加了Swift的新功能到Objective应用程序。

我在目标C(登记)中有一位观察员：

[[NSNotificationCenter defaultCenter] removeObserver:self name:NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(confirmSms) name:NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS object:nil];

并以确认方式：

[[NSNotificationCenter defaultCenter] postNotificationName:NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS object:nil];

如何在Swift中观察这一点？我试过了

NotificationCenter.default.removeObserver(self,
                                                  name: NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS,
                                                  object:nil);

NotificationCenter.default.addObserver(self,
                                              selector:#selector(self.confirmationSmsSent),
                                              name: NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS,
                                              object: nil);

我得到了

未解析标识符“NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS”的使用

谢谢

//编辑：

我已在Obj-C中声明：

NSString *const NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS = @"confirmationSMSSent";

这个还能用吗？

let name: NSNotification.Name = NSNotification.Name("Your_Notification_Name_Key_String") //NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS

当我用

NotificationCenter.default.addObserver(self, selector:#selector(self.confirmationSmsSent(_:)), name: name, object: nil)

func confirmationSmsSent(notification: NSNotification) {

}

我搞错了

类型'MyController‘的值没有成员'confirmationSmsSent’

在……上面

selector:#selector(self.confirmationSmsSent(_:))，名称:名称，对象:0)

Answer 1

在Swift 3中，语法发生了变化。您必须定义NSNotification.Name的变量

let name: NSNotification.Name = NSNotification.Name("Your_Notification_Name_Key_String") //NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS

//Add Notification
NotificationCenter.default.addObserver(self, selector:#selector(self.yourSelector(_:)), name: name, object: nil)

//Remove Notification Observer
NotificationCenter.default.removeObserver(self, name: name, object: nil)

//Your Selector
func yourSelector(_ notification: Notification) {
//Code
}

Answer 2

这是因为您还没有声明NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS。

通常通知名称只是一个字符串，顺便说一句，您必须将其转换为嵌套的NSNotification.Name类型。

let NOTIFICATION_SERVER_SENT_CONFIRMATION_SMS = NSNotification.Name("<some string>")

Answer 3

最有用的迅捷代码是扩展。

extension Notification.Name {
static let someNewName = "ThatsItImAwsome" 
} 

内帖使用情况：

.someNewKey

这是：

NotificationCenter.default.addObserver(self, selector:#selector(self.yourSelector(_:)), name: .someNewKey, object: nil)