CODEWITHSUNDEEP
iosswiftuiviewcontrollerstoryboardsegue
jonhurlock
jonhurlock

Reputation: 1908

Swift Changing View with performSegueWithIdentifier / programmatically

So I am trying to programmatically change views when some condition is triggered.

I have created a simplistic project, whereby I want to change to View 2 from View 1, once View 1 has loaded. In reality, there is some logical operation that checks if some variable is true, then it invokes the performSegueWithIdentifier function, however to keep this as simple as possible I have removed that code.

The steps I have performed are, firstly to create two views: Showing Two Views

I then click View 1, and inspect its properties and then created a manually triggered segue to View 2 Connecting Manual Segue

I selected the 'Show' option, so now my Views are connected by a segue Connected Manual Segue Then under attribute inspector, I give the storyboard segue and identifier of "GoToView2". Naming Segue From there I go to the ViewController.swift file, and in the viewDidLoad function. I insert performSegueWithIdentifier code:

self.performSegueWithIdentifier("GoToView2", sender: self)

Adding PerformSegueWithIdentifier Code

However, when I then run the code. View 2 does not load, and only View 1 appears in the simulator.

Any help and explanation would be greatly appreciated.

Upvotes: 2

Views: 2235

Answers (2)

Nick Shepherd
Nick Shepherd

Reputation: 56

I have had the same problem with attempting to perform a segue inside the viewDidLoad function, and the error that comes up seems to be that the view you are attempting to load with the segue is not in the window hierarchy.

Changing the call to viewDidAppear seemed to fix the issue as mentioned in this other post: whose view is not in the window hierarchy (note the language is objective-c not swift, but it can be translated).

It seems you have to be careful at what point in the view lifecycle you want to change it to another view controller - at viewDidLoad all the views in the storyboard are not available.

BTW, without having a conditional in there, the segue will be fired (and load the view controller) every time the view is loaded!

Upvotes: 4

Kelvin Lau
Kelvin Lau

Reputation: 6781

I am working on a project that does exactly what you want to do. Perform segue with identifier is the right thing to do. My project also does the check in viewDidLoad.

All your steps look fine, so I believe it's a subtle issue. Check the identity inspector to see if you connected the view controller with view 1

Upvotes: 0

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