Storyboard segues causing memory leaks

by

You aren’t using the modal segues correctly. The way you have implemented it, you are creating a new instance of each view controller when you segue instead of returning to the instance you came from. That is why your memory usage continues to increase.

Before iOS 6, the correct way to handle this was to:

1) define a method such as viewController2Done in view controller 1
2) in view controller 2, create a property called delegate of type id.
3) in prepareToSegue for view controller 1, set delegate in view controller 2 to self
4) in view controller 2, when it is time to return to view controller 1, call [delegate viewController2Done]
5) in viewController2Done call [self dismissModalViewControllerAnimated:YES]

This method still works in iOS 6, but there is also a new unwind segue that can be used instead. To use it, you would define a method in your view controller 1 like so:

Objective-C:

- (IBAction)unwindFromViewController2:(UIStoryboardSegue *)segue
{
    NSLog(@"and we are back");
}

Swift:

@IBAction func unwindFromViewController2(_ segue: UIStoryboardSegue) {
    print("and we are back")
}

Then you’d control drag from the button in view controller 2 to the orange exit icon in the bar above the view controller in the Storyboard. In the pop up, you’d select unwindFromViewController2 and voila, you’re done.

enter image description here

More Related Contents:

  1. Passing variables between view controllers
  2. Displaying images on another view controller when button is clicked
  3. Get to UIViewController from UIView?
  4. Passing Data between View Controllers in Swift
  5. Programmatically set the initial view controller using Storyboards
  6. Xcode, where to assign the segue identifier
  7. viewWillDisappear: Determine whether view controller is being popped or is showing a sub-view controller
  8. Prepare for Segue in Swift
  9. Segue to another storyboard?
  10. iOS 9 Segue Causes App To Freeze (no crash or error thrown)
  11. How to get UIScrollView vertical direction in Swift?
  12. Instantiate View Controller from Storyboard vs. Creating New Instance
  13. Prevent segue in prepareForSegue method?
  14. Can I use autolayout to provide different constraints for landscape and portrait orientations?
  15. Proper use of loadView and viewDidLoad with UIViewController without nibs/xibs
  16. Expected declaration error for making high score [duplicate]
  17. difference between presentViewController and UINavigationController?
  18. Embed a UIViewController in a NavigationController using segues
  19. UIViewController viewDidLoad vs. viewWillAppear: What is the proper division of labor?
  20. Change Default Scrolling Behavior of UITableView Section Header
  21. modal View controllers – how to display and dismiss
  22. How to determine UIWebView height based on content, within a variable height UITableView?
  23. Perform Segue on ViewDidLoad
  24. iOS 7 custom back button
  25. Xcode 4.5 and iOS 4.2.1 incompatibility
  26. Given a view, how do I get its viewController?
  27. UITextView – setting font not working with iOS 6 on XCode 5
  28. Simulator slow-motion animations are now on?
  29. In SwiftUI, how to use UIHostingController inside an UIView or as an UIView?
  30. “Cannot connect to iTunes Store” in-app purchases

Leave a Comment