问题
It's very important for my app to be notified every time the user kills my app (not moving it to the background, but actually quitting it altogether by double-tapping the Home button and swiping my app screenshot up). I know applicationWillTerminate() barely ever gets called, so I was wondering what the safest way is to be notified when a user will kill the app. It seems very unlikely that Apple hasn't provided ANY form of solution for this, as a lot of iOS users make it a custom to kill apps when they're done using it, so it would be really really REALLY weird if it would be impossible to catch this event. The only thing I need to do is fire off a URLRequest to send some updating instructions to my web service.
回答1:
I get more consistency when I add an observer to handle UIApplicationWillTerminateNotification. It gets called when the user double-taps the Home button and swipe the app to kill it.
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool
{
NSNotificationCenter.defaultCenter().addObserver(self, selector:#selector(AppDelegate.onAppWillTerminate(_:)), name:UIApplicationWillTerminateNotification, object:nil)
return true
}
func onAppWillTerminate(notification:NSNotification)
{
print("onAppWillTerminate")
}
来源：https://stackoverflow.com/questions/40850846/send-request-to-web-service-when-app-gets-killed-swift-3