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2014/10/15 ¤U¤È 10:12:16
iphone Programming Glossary: observerHow to check for an active Internet Connection on iPhone SDK? http://stackoverflow.com/questions/1083701/how-to-check-for-an-active-internet-connection-on-iphone-sdk via WWAN. self.hostActive YES break 9 In your dealloc or viewWillDisappear or similar method remove yourself as an observer void viewWillDisappear BOOL animated NSNotificationCenter defaultCenter removeObserver self Note There might be an instance.. removeObserver self Note There might be an instance using viewWillDisappear where you receive a memory warning and the observer never gets unregistered so you should account for that as well. Note The domain you use doesn't matter. It's just testing..
When to use restoreCompletedTransactions for in-app purchases? http://stackoverflow.com/questions/1757467/when-to-use-restorecompletedtransactions-for-in-app-purchases SKPaymentQueue's restoreCompletedTransactions Observations I know it's recommended to always register a transaction observer to receive pending transactions that make their way back to the app but this is a different question. It looks like restoreCompletedTransactions..
Send and receive messages through NSNotificationCenter in Objective-C? [closed] http://stackoverflow.com/questions/2191594/send-and-receive-messages-through-nsnotificationcenter-in-objective-c share improve this question @implementation TestClass void dealloc If you don't remove yourself as an observer the Notification Center will continue to try and send notification objects to the deallocated object. NSNotificationCenter.. removeObserver self super dealloc id init self super init if self return nil Add this instance of TestClass as an observer of the TestNotification. We tell the notification center to inform us of TestNotification notifications using the receiveTestNotification..
Delegates Vs. Notifications in iPhoneOS http://stackoverflow.com/questions/2232694/delegates-vs-notifications-in-iphoneos you can use multiple notification names but all notifications end up in the same method on the side of the observer possibly requiring a nasty switch statement . Only you can decide what pattern is more appropriate for you. In any case.. the delegate message. In many cases the view controller should change the model and then the model should inform its observers or its delegate that it has been changed. Implementing a delegate pattern is simple In your ChildViewController.h declare..
Dismissing UIAlertViews when entering background state http://stackoverflow.com/questions/3105974/dismissing-uialertviews-when-entering-background-state .m part of a subclass of UIAlertView. Edit Cédric I have added a way to catch calls to delegate methods and remove the observer then to avoid multiple registrations to the notification center. #import UIAlertViewAutoDismiss.h #import objc runtime.h..
Show iPhone soft keyboard even though a hardware keyboard is connected http://stackoverflow.com/questions/3326189/show-iphone-soft-keyboard-even-though-a-hardware-keyboard-is-connected CGRectMake 0 759 768 265 Then in our applicationDidFinishLaunching we added this notification observer so we would get an event anytime a text field began editing Setup the textFieldNotifications NSNotificationCenter defaultCenter..
Key Value Observing with an NSArray http://stackoverflow.com/questions/3478451/key-value-observing-with-an-nsarray whenever the contents of the array changes. Depending on the NSKeyValueObservingOptions you use when adding your observer you can also get the incremental changes that are made ”a cool feature but you may not need it in this case. Note NSArrayController..
How to get UIKeyboard size with Apple iPhone SDK http://stackoverflow.com/questions/3546571/how-to-get-uikeyboard-size-with-apple-iphone-sdk the userInfo dictionary comes from an NSNotification instance. It's passed to your method that you register with an observer. For example void someMethodWhereYouSetUpYourObserver This could be in an init method. NSNotificationCenter defaultCenter..
Handling applicationDidBecomeActive http://stackoverflow.com/questions/3639859/handling-applicationdidbecomeactive iphone ios4 uiapplicationdelegate share improve this question Any class in your application can become an observer for different notifications in the application. When you create or load your view controller you'll want to register it.. notifications in the application. When you create or load your view controller you'll want to register it as an observer for the UIApplicationDidBecomeActiveNotification and specify which method that you want to call when that notification gets.. object nil Don't forget to clean up after yourself In dealloc remember to remove yourself as the observer NSNotificationCenter defaultCenter removeObserver self More information about the Notification Center . share improve this..
When to use a colon with a @selector http://stackoverflow.com/questions/4953623/when-to-use-a-colon-with-a-selector to the action argument. The action argument takes a @selector just like the selector argument while setting up an observer for an NSNotification so I figured I was doing the right thing. However with the following code self.callToActionButton..
Prevent indentation of UITableViewCell (contentView) while editing http://stackoverflow.com/questions/5789467/prevent-indentation-of-uitableviewcell-contentview-while-editing oldFrame NSStringFromCGRect newFrame if newFrame.origin.x 0 self.contentView.frame oldFrame add the cell as an observer for frame changes somewhere in initialization self.contentView addObserver self forKeyPath @ frame options NSKeyValueObservingOptionOld.. addObserver self forKeyPath @ frame options NSKeyValueObservingOptionOld context nil IMPORTANT remove the cell as an observer in dealloc self.contentView removeObserver self forKeyPath @ frame This will only allow the frame to change to values with..
When does an associated object get released? http://stackoverflow.com/questions/6039309/when-does-an-associated-object-get-released 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 in object..
http://stackoverflow.com/questions/7010547/uitextfield-text-change-event but it did not fulfill my need exactly. Since until it returns YES the textField texts are not available to other observer methods. e.g. in my code calculateAndUpdateTextFields did not get the updated text the user has typed. Is their any way..
Core Data and threads / Grand Central Dispatch http://stackoverflow.com/questions/7540801/core-data-and-threads-grand-central-dispatch mergeChangesFromContextDidSaveNotification notification waitUntilDone YES And don't forget to remove the observer from the notification center once you are done with the background thread context. NSNotificationCenter defaultCenter removeObserver..
Why is object not dealloc'ed when using ARC + NSZombieEnabled http://stackoverflow.com/questions/8408071/why-is-object-not-dealloced-when-using-arc-nszombieenabled any illumination. Second it is true that a workaround for this specific crash is to remove actionsController as an observer when secondaryViewController is deallocated. I have also found that if I explicitly set actionsController nil when secondaryViewController..
Equivalent of iOS NSNotificationCenter in Android? http://stackoverflow.com/questions/10327200/equivalent-of-ios-nsnotificationcenter-in-android question In Android there is not a central notification center as in ios. But you can basically use Observable and Observer objects to achieve your task. You can define a class like something below just modify it for singleton use and add synchronized.. String Observable observables public ObservingService observables new HashMap String Observable public void addObserver String notification Observer observer Observable observable observables.get notification if observable null observable.. public ObservingService observables new HashMap String Observable public void addObserver String notification Observer observer Observable observable observables.get notification if observable null observable new Observable observables.put..
http://stackoverflow.com/questions/1900352/what-is-nsnotification NSNotificationCenter vs. AppDelegate iphone nsnotification share improve this question Apple has provided an Observer Pattern in the Cocoa library called the NSNotificationCenter. The basic idea is that a listener registers with a broadcaster.. notifications when the UIApplication object reaches certain states. In many respects it is a specialized one to one Observer pattern. You can read more about it here http stackoverflow.com questions 652460 what is the appdelegate for and how do..
Apple In app purchase StoreKit error http://stackoverflow.com/questions/4087658/apple-in-app-purchase-storekit-error to purchase from AppStore delegate self cancelButtonTitle @ OK otherButtonTitles nil alert show alert release Observer void paymentQueue SKPaymentQueue queue updatedTransactions NSArray transactions for SKPaymentTransaction transaction in..
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 Key Value Observing KVO Allowing one 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..
http://stackoverflow.com/questions/5872788/apple-in-app-purchase payment I have added the transaction observer in applicationDidFinishLaunching method of AppDelegate Transaction Observer is a class TransactionObserver observer observer TransactionObserver alloc init SKPaymentQueue defaultQueue addTransactionObserver.. transaction observer in applicationDidFinishLaunching method of AppDelegate Transaction Observer is a class TransactionObserver observer observer TransactionObserver alloc init SKPaymentQueue defaultQueue addTransactionObserver observer the TransactionObserver.m.. method of AppDelegate Transaction Observer is a class TransactionObserver observer observer TransactionObserver alloc init SKPaymentQueue defaultQueue addTransactionObserver observer the TransactionObserver.m class @implementation TransactionObserver..
What is the AppDelegate for and how do I know when to use it? http://stackoverflow.com/questions/652460/what-is-the-appdelegate-for-and-how-do-i-know-when-to-use-it notifications when the UIApplication object reaches certain states. In many respects it is a specialized one to one Observer pattern. This means that the area of concern for the AppDelegate is handling special UIApplication states. The most important..
What is the difference between Notifications, Delegates, and Protocols? http://stackoverflow.com/questions/7118598/what-is-the-difference-between-notifications-delegates-and-protocols Delegates and Protocols What is the difference between Protocols or Delegates and NSNotifications What is an Observer and how does it work iphone objective c delegates notifications protocols share improve this question You can find..
How to stop the Observer in NSNotification to called twice? http://stackoverflow.com/questions/7751191/how-to-stop-the-observer-in-nsnotification-to-called-twice to stop the Observer in NSNotification to called twice I have an observer of NSNotification which is called twice. I do not know what to do.. twice. I do not know what to do with it. I googled it but no solution found. NSNotificationCenter defaultCenter addObserver self selector @selector connectedToServer name @ ConnectedToServer object nil void connectedToServer NSNotification notification.. lines will register the observer self for the same notification aSelector twice. NSNotificationCenter defaultCenter addObserver self selector aSelector name aName object nil NSNotificationCenter defaultCenter addObserver self selector aSelector name..
Why doesn't Remove Observer from NSNotificationCenter:addObserverForName:usingBlock get called http://stackoverflow.com/questions/8477629/why-doesnt-remove-observer-from-nsnotificationcenteraddobserverfornameusingbl doesn't Remove Observer from NSNotificationCenter addObserverForName usingBlock get called I'm confused on why the observer is never removed in.. doesn't Remove Observer from NSNotificationCenter addObserverForName usingBlock get called I'm confused on why the observer is never removed in the following code. In my viewDidAppear.. never removed in the following code. In my viewDidAppear I have the following void viewDidAppear BOOL animated id gpsObserver NSNotificationCenter defaultCenter addObserverForName FI_NOTES kNotificationsGPSUpdated object nil queue NSOperationQueue..
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