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2014/10/15 ¤U¤È 10:10:49

iphone Programming Glossary: kvo

Get notification when NSOperationQueue finishes all tasks

http://stackoverflow.com/questions/1049001/get-notification-when-nsoperationqueue-finishes-all-tasks

notification is received. iphone asynchronous queue notifications nsoperation share improve this question Use KVO to observe the operations property of your queue then you can tell if your queue has completed by checking for queue.operations.. a property named queue EDIT iOS 4.0 now has an NSOperationQueue.operationCount property which according to the docs is KVO compliant. This answer will still work in iOS 4.0 however so it's still useful for backwards compatibility. share improve..

UIScrollView. Any thoughts on implementing “infinite” scroll/zoom?

http://stackoverflow.com/questions/1493950/uiscrollview-any-thoughts-on-implementing-infinite-scroll-zoom

set the content offset so that you're seeing the middle of the handled view. Then just watch the content offset using KVO or some other method and if you near any edge update the content of the view with a new set of content offset appropriately..

Best way to implement Enums with Core Data

http://stackoverflow.com/questions/1624297/best-way-to-implement-enums-with-core-data

expect an NSNumber object rather than a scalar type and you'll run into trouble if anything in the bindings or KVO systems try and access your value. PaymentFrequency itemTypeRaw return PaymentFrequency self itemType intValue void setItemTypeRaw.. self setItemType NSNumber numberWithInt type Finally you should implement keyPathsForValuesAffecting Key so you get KVO notifications for itemTypeRaw when itemType changes. NSSet keyPathsForValuesAffectingItemTypeRaw return NSSet setWithObject..

How do I zoom an MKMapView to the users current location without CLLocationManager?

http://stackoverflow.com/questions/2473706/how-do-i-zoom-an-mkmapview-to-the-users-current-location-without-cllocationmanag

solution and not turned up anything close. iphone mkmapview share improve this question You have to register for KVO notifications of userLocation.location property of MKMapView . To do this put this code in viewDidLoad of your ViewController.. options NSKeyValueObservingOptionNew NSKeyValueObservingOptionOld context NULL Then implement this method to receive KVO notifications void observeValueForKeyPath NSString keyPath ofObject id object change NSDictionary change context void..

Use Key Value Observing to get a KVO callback on a UIView's frame

http://stackoverflow.com/questions/4874288/use-key-value-observing-to-get-a-kvo-callback-on-a-uiviews-frame

Key Value Observing to get a KVO callback on a UIView's frame I want to watch for changes in a UIView 's frame bounds or center property. How can I use.. iphone ios objective c uiview key value observing share improve this question Currently it's not possible to use KVO to observe a view's frame. Properties have to be KVO compliant to be observable. Sadly properties of the UIKit framework.. share improve this question Currently it's not possible to use KVO to observe a view's frame. Properties have to be KVO compliant to be observable. Sadly properties of the UIKit framework are generally not observable as with any other system..

What are the key concepts for an iPhone Developer to learn? [closed]

http://stackoverflow.com/questions/5677655/what-are-the-key-concepts-for-an-iphone-developer-to-learn

coding patterns techniques and some general tidbits that you should know about. Coding Patterns Key Value Observing KVO Allowing one object to respond to changes of another object's properties by registering the Observer with the target object... to respond to changes of another object's properties by registering the Observer with the target object. For more on KVO see Apple's Key Value Observing Programming Guide . Model View Controller Pattern In the Model View Controller Pattern MVC..

When does an associated object get released?

http://stackoverflow.com/questions/6039309/when-does-an-associated-object-get-released

I'm attaching object B via associative reference to object A. Object B observes some properties of object A through KVO. The problem is that object B seems to be deallocated after object A meaning its too late to remove itself as a KVO observer.. KVO. The problem is that object B seems to be deallocated after object A meaning its too late to remove itself as a KVO observer of object A. I know this because I'm getting NSKVODeallocateBreak exceptions followed by EXEC_BAD_ACCESS crashes.. after object A meaning its too late to remove itself as a KVO observer of object A. I know this because I'm getting NSKVODeallocateBreak exceptions followed by EXEC_BAD_ACCESS crashes in object B's dealloc. Does anyone know why object B is deallocated..

ObjectiveC ivars or @property

http://stackoverflow.com/questions/6942439/objectivec-ivars-or-property

in the init or dealloc methods because a subclass might have overridden them or in dealloc you might set off a KVO notification. From Sam's answer and comments If you want a property regardless you could use a private interface at the..

To ARC or not to ARC? What are the pros and cons?

http://stackoverflow.com/questions/8760431/to-arc-or-not-to-arc-what-are-the-pros-and-cons

need to know the rules when you start messing around with void pointers to id which you continue to need to perform KVO correctly . And blocks... well block memory management is just weird. So my point is that the underlying memory management..

Why do I have to call super -dealloc last, and not first?

http://stackoverflow.com/questions/909856/why-do-i-have-to-call-super-dealloc-last-and-not-first

they are released when you call super dealloc . It is always safe to call the superclass in the last line. Also KVO and depended triggered keys can produce side effects if they are depended of already released member variables. share..