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    <p>Welcome to iOS programming. Your crash is a memory management issue. It may take you a bit to get the hang of it but memory management gets way easier if you just follow one rule:</p> <p><strong>an object needs to release anything it retains (alloc is equivalent to retain)</strong></p> <p>In this case, your view controller is releasing itself and it definitely did not retain itself. Here's how the sequence works with a navigation controller:</p> <ol> <li><p>The navigation controller is initialized with a root view controller (the first one on its stack). Lets call this <code>firstViewController</code></p></li> <li><p>A user action tells <code>firstViewController</code> to initialize <code>secondViewController</code> and push it onto the navigation controller. In most cases, <code>firstViewController</code> will release the instance of <code>secondViewController</code> after pushing it. At this point, <code>firstVC</code> is done with <code>secondVC</code>. The navigation controller is now retaining <code>secondVC</code></p></li> <li><p>User touches the back button on the navigation bar of <code>secondVC</code>. The navigation controller will pop <code>secondVC</code> from the stack and release it. As long as no other object is retaining it, <code>secondVC</code> will get be dealloc'ed.</p></li> <li><p>Now user is back in <code>firstVC</code>. They can do the same user action which will init and push a new instance of <code>secondVC</code>.</p></li> </ol> <p>Hope that helps a bit.</p> <p>I'd also recommend you (re)read the Apple docs and look at the sample code referenced in the framework docs.</p> <p><a href="http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/Introduction/Introduction.html" rel="nofollow">http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/Introduction/Introduction.html</a></p>
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    1. COThank's for your answer, but the example you've given is too basic for my case - I want to decide which viewcontrollers to dealloc and when (sometimes, even when it is popped, i want it to save it's state so when the user returns, it gets brought up immiediately). Right now i've worked around this, and set up MainView controller as a observer of notification center - and other view controllers post notifications if they want to be dealloc'ed or just popped from the stack.
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      1. USPeter Sarnowski
    2. COI really don't know what you're trying to do but I would still recommend reading and understanding the docs. Start simple and add complexity as you need it and things are working. Best of luck.
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