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Is there anything similar to the viewDidLoad of UIViewController for a UIView??? I need to be notified as soon as a UIView has loaded (Subclass of UIView), and perform some actions.

Alex Cio
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aryaxt
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1 Answers1

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Depending on what kind of actions you need to perform, there are several techniques:

  1. -(id)initWithFrame:(CGRect)frame - UIView's designated initializer; always sent to a UIView to initialize it, unless the view is loaded from a nib;
  2. -(id)initWithCoder:(NSCoder *)coder - always sent to initialize a UIView whenever the view is loaded from a nib;
  3. -(void)awakeFromNib - sent after all the objects in the nib are initialized and connected; applicable only if you load the object from a nib; you must call super;
  4. -(void)willMoveToSuperview:(UIView *)newSuperview - sent immediately before the view is added as a subview to another view; newSuperview may be nil when you remove the view from its superview;
  5. -(void)willMoveToWindow:(UIWindow *)newWindow - sent immediately before the view (or its superview) is added to a window; newWindow may be nil when you remove the view from a window;
  6. -(void)didMoveToSuperview - sent immediately after the view is inserted into a view hierarchy;
  7. -(void)didMoveToWindow - sent immediately after the view gets its window property set. -

Basically, you can choose to perform your actions during initialization (1 & 2), after loading from a nib (3), before insertion into a view hierarchy (4 & 5) and after that (6 & 7).

Muhammad Nabeel Arif
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Costique
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  • Thanks a lot perfect answer (very detailed). I was modifying a segmented control and it wasn't displaying the changes because I was calling the modification method during init, I moved it to didMoveToWindow and it fixed all the problems – aryaxt Dec 21 '10 at 18:55
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    It seems all of this happened before viewDidLoad in viewController – Alex Chan Apr 17 '15 at 08:53
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    `-(void)willMoveToSuperview:(UIView *)newSuperview` was the cure to all my problems, thank you very much! – Erion S Jul 15 '15 at 15:05
  • I forgot again that some things do not work if you keep caling them inside a UIView at the very beginning of the initialization process..... So doing it in 7 or performing with delay from there will always work! :) – Alex Cio Dec 03 '16 at 23:51