removeFromParentViewController

removeFromParentViewController is a method available on the UIViewController class in Apple's UIKit framework. Its primary purpose is to remove a child view controller from its parent view controller. When a view controller is added as a child to another, it typically means that the parent controller is managing the lifecycle and presentation of the child. Calling removeFromParentViewController on the child controller signals to the parent that it should no longer be responsible for it.

This method handles several important tasks: it detaches the child's view from the parent's view hierarchy, stops the child's view controller lifecycle methods from being called by the parent, and removes any container view relationships that might exist. It is crucial for proper memory management and to prevent unexpected behavior when view controllers are dynamically added and removed during the app's runtime.

For example, in a tabbed interface or a navigation controller, the parent view controller manages the presentation and removal of its child view controllers as the user navigates. When a tab is deselected or a view controller is popped from a navigation stack, the parent implicitly or explicitly calls removeFromParentViewController on the outgoing child. Developers often use this method directly when implementing custom container view controllers or when programmatically managing the display of view controllers within a specific section of their app's UI. It ensures that the child controller is properly deallocated and its associated views are removed from the screen, preventing potential memory leaks or visual glitches.