iOS 中的不同背景模式

Different background modes in iOS

为了识别我的应用程序进入了后台模式 [一次短按主页按钮]我使用这个功能:

func applicationDidEnterBackground(_ application: UIApplication) {
    //...
}

但是我如何识别我的应用进入了应用切换模式[两次短按主页按钮]?在这种情况下不会调用方法 applicationDidEnterBackground

试试这个:

    func applicationWillResignActive(_ application: UIApplication) {
        // 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, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }