如何在applicationDidBecomeActive中确定它是否是最初的iPhone应用程序启动？

var isFirstLaunch = true

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // 设置默认值
    UserDefaults.standard.register(defaults: ["isFirstLaunch": true])
    isFirstLaunch = UserDefaults.standard.bool(forKey: "isFirstLaunch")
    return true
}

func applicationDidBecomeActive(_ application: UIApplication) {
    if isFirstLaunch {
        // 这是应用程序的第一次启动
        isFirstLaunch = false
        UserDefaults.standard.set(false, forKey: "isFirstLaunch")
    } else {
        // 这不是应用程序的第一次启动
    }
}