swift - 如何在应用程序启动时显示警报

Question

我想在我的应用程序当天首次启动时发出提醒。我认为执行此操作的地方是 appDelegate(如果我错了请纠正我)。我有两个问题，一个:我不知道该函数应该驻留在 appDelegate 中的哪个函数下(目前只选择了 func 应用程序)，第二个:我不知道如何将 alertController 呈现给 View 开了。到目前为止，我已经做到了这一点

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    if checkIfNewDay() {
        let alert = UIAlertController("some title": alertTitle, message: "some message", preferredStyle: .Alert)
        alert.addAction(UIAlertAction(title: "Okay", style: .Cancel, handler: nil))

        // What to do here????
    }

我应该用什么代码替换评论？

Answer 1

尝试使用这个方法:applicationDidBecomeActive

func applicationDidBecomeActive(application: UIApplication) {
     //This method is called when the rootViewController is set and the view.
    if checkIfNewDay() {
       let alert = UIAlertController("some title": alertTitle, message: "some message", preferredStyle: .Alert)
       alert.addAction(UIAlertAction(title: "Okay", style: .Cancel, handler: nil))
       self.window?.rootViewController?.presentViewController(alert, animated: true, completion: nil)
    }
}