如何在 iOS Swift 的启动（启动）屏幕上显示警报 5

Question

I want to show an alert on the Launch screen in iOS using Swift 5. Basically, I am checking if a certain condition is met, and if it isn't, then show the alert with a simple "OK" or "Dismiss".

Here is the code, which is not working:

func application(_ application: UIApplication, willFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {

    if conditionMet
            {
                print("Condition met!")
            }
            else
            {
                
                let storyboard : UIStoryboard = UIStoryboard(name: "Launch Screen", bundle: nil)
                let launchScreenCtrler = storyboard.instantiateViewController(identifier: "LAUNCH_SCREEN")
                let alertViewFrame = CGRect(x: 100, y: 300, width: 120, height: 80)
                let newView : UIView = UIView(frame: alertViewFrame)
                launchScreenCtrler.view.addSubview(newView)
                launchScreenCtrler.view.bringSubviewToFront(newView)
  
                alert.show(launchScreenCtrler, sender: newView)
     
            }
}

Any ideas as to what am I missing?

Thanks,

Answer 1

The launch screen (the one you are presumably setting up in LaunchScreen.storyboard ) is not "interactable": you can design its UI using auto layout in interface builder, but that's it.

The best place to show an alert based on some condition as soon as the app launches is from the root view controller of your current window, aka the first view controller that will be instantiated.