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iOS

Posted by Pierre Smith
Pierre Smith
11,842 Points

Swift. I'm trying to get my locationManager to update users location work in applicationDidBecomeActive.

So i'm trying to get my users location every time the application becomes active. I initiated my location manager in the mainViewController.swift and have all the functionality in the locationManager: didUpdateLocation method so I want to access this location manager in my appDelegate.swift file but I can't seem to figure out how to get this done.

My first attempt was using inheritance like this: appDelegate: mainViewController, UIApplicationDelegate { }

which allowed me to use the locationManager I initiated but it never actually seemed to call the locationManager:didUpdateLocation method because I see no changes made to my view nor in debug

My second attempt was creating a instance of the class "mainViewController" and it just allows for the methods to be called and on top of that it wants it to be called in a manner that is beyond me.

example: 

var viewController = mainViewController()
mainViewController.locationManager(self)

why can't I use the locationManager I initiated in my main view controller like this 

mainViewController.locationManager.startUpdatingLocation()

and how do I achieve this in the applicationDidBecomeActive method.

1 Answer

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

You are currently creating a new MainViewController instance. What you want to do is retrieve the current instance of MainViewController the app is using, not create a totally new one

is your main view controller the root view controller of your app? if so you can access it from within the app delegate and cast it to your MainViewController like so:

var rootViewController = self.window!.rootViewController as MainViewController

that will retrieve the instance of the main view controller you need, instead of creating a totally new one like you currently are trying to do.

then you should be able to access the locationManager:

var rootViewController = self.window!.rootViewController as MainViewController
rootViewController.locationManager.startUpdatingLocation
Pierre Smith
Pierre Smith
11,842 Points

ok thank you. So I tried putting that and I'm given a AppDelegate -> 0 ->AppDelegate does not have member named 'window'.

And how to I check which view controller is my root view controller

Stone Preston
Stone Preston
42,016 Points

in your storyboard your root view controller is the one with the arrow next to it. its the first view controller in the app.

hmm im not sure why you are getting that error, the app delegate should have an optional window property. you are using storyboards correct?

Pierre Smith
Pierre Smith
11,842 Points

yes I am. then yes it is my root controller

Pierre Smith
Pierre Smith
11,842 Points

Sorry I decided to try it again and it worked. Turns out It has to be created in one of the methods and not made globally for some reason.