WatchOS：获取 applicationDidBecomeActive 通知

Question

我正在制作一个框架，当我的苹果手表进入背景和前景时需要做一些事情。

我正在为 Apple watch 寻找与此 iOS 代码等效的代码，因为 UIApplication 不再存在于 UIKit 中：

let notificationCenter = NSNotificationCenter.defaultCenter()
notificationCenter.addObserver(self, selector: "applicationDidEnterBackground", name: UIApplicationDidEnterBackgroundNotification, object: nil)

你能帮忙的话，我会很高兴

Answer 1

从 watchOS 7 开始，添加了以下内容：

WKExtension.applicationDidBecomeActiveNotification
WKExtension.applicationDidEnterBackgroundNotification
WKExtension.applicationDidFinishLaunchingNotification
WKExtension.applicationWillEnterForegroundNotification
WKExtension.applicationWillResignActiveNotification

来源： https ://developer.apple.com/documentation/WatchKit/wkextension

Answer 2

似乎 WatchOS 相当于

let notificationCenter = NSNotificationCenter.defaultCenter()
notificationCenter.addObserver(self, selector: "applicationDidEnterBackground", name: UIApplicationDidEnterBackgroundNotification, object: nil)

简直是

let notificationCenter = NSNotificationCenter.defaultCenter()
notificationCenter.addObserver(self, selector: "applicationDidEnterBackground", name: "UIApplicationDidEnterBackgroundNotification", object: nil)

只需要用等效的字符串替换 emum

Answer 3

最接近的是applicationDidBecomeActive和applicationWillResignActive

class ExtensionDelegate: NSObject, WKExtensionDelegate {

  func applicationDidFinishLaunching() {
      // Perform any final initialization of your application.
  }

  func applicationDidBecomeActive() {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.    
  }

  func applicationWillResignActive() {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, etc.
  }
}