objective c - iPhone Method Questions (dealloc an viewDidUnload) -

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i have been working on app, , book read said put these statements viewdidunload , dealloc methods. other information should go here? have buttons , labels in program. need them?

i want efficiently running application.

here's code: 

- (void)viewdidunload {         // release retained subviews of main view.         // e.g. self.myoutlet = nil;         self.doublepicker = nil;         self.color = nil;         self.choice = nil;         [super viewdidunload];     }      - (void)dealloc {         [doublepicker release];         [color release];         [choice release];         [super dealloc];     }

you should release iboutlets , other ui elements in viewdidunload. other data allocated in view controller (as iboutlets) should released in dealloc method. that's because view can loaded , unloaded multiple times during lifetime of view controller. example, view can unloaded if not visible, data behind (in view controller) still needs kept in memory. when both view , controller no longer needed, dealloc method called.


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