Comments on: Dealing With Memory Warnings in View Controllers http://www.fieryrobot.com/blog/2008/10/03/dealing-with-memory-warnings-in-view-controllers/ Defender of Corporate Headquarters Fri, 09 Dec 2011 06:14:31 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: nevyn http://www.fieryrobot.com/blog/2008/10/03/dealing-with-memory-warnings-in-view-controllers/comment-page-1/#comment-209896 nevyn Wed, 20 Apr 2011 15:46:04 +0000 http://www.fieryrobot.com/blog/?p=107#comment-209896 <p>Feeding Google: Since 3.0, there is - (BOOL)isViewLoaded, which is an explicit way of finding out if the view is loaded rather than the implicit way through superview.</p> Feeding Google: Since 3.0, there is – (BOOL)isViewLoaded, which is an explicit way of finding out if the view is loaded rather than the implicit way through superview.

]]> By: Nate http://www.fieryrobot.com/blog/2008/10/03/dealing-with-memory-warnings-in-view-controllers/comment-page-1/#comment-173731 Nate Wed, 08 Jul 2009 05:34:15 +0000 http://www.fieryrobot.com/blog/?p=107#comment-173731 <p>This technique really isn't robust either. The reason you can't test your view against nil, is that self.view (or [self view]) will recreate the view if it's nil.</p> <p>Calling, self.view.superview will simply do the same thing, as it calls self.view before accessing the superview property. Even if you put the call to self.view.superview before calling [super didReceiveMemoryWarning], how do you know you won't get another memory warning later in the run?</p> <p>I don't know that Apple guarantees this method will only be called once. The viewDidUnload callback in OS 3.0 helps, but I still don't know of a good way to handle this in OS < 3.0.</p> This technique really isn’t robust either. The reason you can’t test your view against nil, is that self.view (or [self view]) will recreate the view if it’s nil.

Calling, self.view.superview will simply do the same thing, as it calls self.view before accessing the superview property. Even if you put the call to self.view.superview before calling [super didReceiveMemoryWarning], how do you know you won’t get another memory warning later in the run?

I don’t know that Apple guarantees this method will only be called once. The viewDidUnload callback in OS 3.0 helps, but I still don’t know of a good way to handle this in OS < 3.0.

]]> By: Raj http://www.fieryrobot.com/blog/2008/10/03/dealing-with-memory-warnings-in-view-controllers/comment-page-1/#comment-149205 Raj Wed, 21 Jan 2009 10:16:03 +0000 http://www.fieryrobot.com/blog/?p=107#comment-149205 <p>Hey great post. I have bookmarked it on http://www.iphonekicks.com/tipsandtricks/iPhone_SDK_Dealing_With_Memory_Warnings_in_View_Controllers</p> Hey great post. I have bookmarked it on http://www.iphonekicks.com/tipsandtricks/iPhone_SDK_Dealing_With_Memory_Warnings_in_View_Controllers

]]> By: Karl Adam http://www.fieryrobot.com/blog/2008/10/03/dealing-with-memory-warnings-in-view-controllers/comment-page-1/#comment-131068 Karl Adam Thu, 09 Oct 2008 00:40:56 +0000 http://www.fieryrobot.com/blog/?p=107#comment-131068 <p>I should also point out that you need to check for the superview first before calling [super didReceiveMemoryWarning] because if you call self.view and it's already been released then you will be loading that view all over again.</p> <p>Also, ALL your viewControllers get this call so you do need to verify you need to tear down your custom views before doing so, otherwise you'll end up with black screens in front of users.</p> I should also point out that you need to check for the superview first before calling [super didReceiveMemoryWarning] because if you call self.view and it’s already been released then you will be loading that view all over again.

Also, ALL your viewControllers get this call so you do need to verify you need to tear down your custom views before doing so, otherwise you’ll end up with black screens in front of users.

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