2014/10/15 下午 10:13:24

iphone Programming Glossary: retains

How do you pass objects between View Controllers in Objective-C?

http://stackoverflow.com/questions/2770460/how-do-you-pass-objects-between-view-controllers-in-objective-c

some method to parse the JSON and build the dictionary self populateDataFromJSON commonData each view controller retains the pointer to NSMutableDictionary and releases it on dealloc self.m_viewControllerOne UIViewControllerOne alloc initWithData..

Managing multiple asynchronous NSURLConnection connections

http://stackoverflow.com/questions/332276/managing-multiple-asynchronous-nsurlconnection-connections

It may seem odd to use this instead of NSMutableDictionary but I do it because this CFDictionary only retains its keys the NSURLConnection whereas NSDictionary copies its keys and NSURLConnection doesn't support copying . Once that's..

Difference between self.ivar and ivar?

http://stackoverflow.com/questions/4142177/difference-between-self-ivar-and-ivar

will call the setName NSString str mutator generated by the compiler which will first release the current string then retains the new string and finally sets name to the retained string. Just calling name foo does nothing more than assigning name..

Passing array between view controllers?

http://stackoverflow.com/questions/4478511/passing-array-between-view-controllers

the model object is a property on your AppController. The controller then has a property for this model object and retains it so that the model object does not go away while the controller lives. The controller then also registers for notifications..

Facebook API - How to cancel Graph Request

http://stackoverflow.com/questions/4958912/facebook-api-how-to-cancel-graph-request

to note the delegate you assign to the request shouldn't ever be dealloc'd and then referenced because the request retains the delegate. See this similar question . Now if you find yourself really needing a cancel method for some other reason.....

Why should I use @properties? [duplicate]

http://stackoverflow.com/questions/5602968/why-should-i-use-properties

do so and a great place to keep that reference is in an instance variable. You could handle the ownership claims i.e. retains and releases each time you assign a new value to that but that would leave a lot of repetitious and trouble prone boilerplate..

What is objc_setAssociatedObject() and in what cases should it be used?

http://stackoverflow.com/questions/5909412/what-is-objc-setassociatedobject-and-in-what-cases-should-it-be-used

At point 1 the string overview is still valid because the OBJC_ASSOCIATION_RETAIN policy specifies that the array retains the associated object. When the array is deallocated however at point 2 overview is released and so in this case also deallocated...

Why does this create a memory leak (iPhone)?

http://stackoverflow.com/questions/612986/why-does-this-create-a-memory-leak-iphone

id may be replaced by a more specific type or @property copy id editMyObject then assignment via self.editMyObject retains or copies the assigned object. Since MyObject alloc init returns a retained object that you as the caller own you have an..

Understanding reference counting with Cocoa and Objective-C

http://stackoverflow.com/questions/6578/understanding-reference-counting-with-cocoa-and-objective-c

were using. Assuming everyone is playing along and retaining releasing according to the rules when one piece of code retains and then releases the object any other piece of code also referencing the object will be unaffected. What can sometimes..

ARC, Blocks and Retain Cycles

http://stackoverflow.com/questions/7761074/arc-blocks-and-retain-cycles

compiler gives a warning that using 'operation' in the block is going to lead to a retain cycle. Under ARC __block now retains the variable. If I add __unsafe_unretained the compiler releases the object immediately so obviously that won't work. I'm..

iPhone fetch data dictionary from keychain

http://stackoverflow.com/questions/7827730/iphone-fetch-data-dictionary-from-keychain

to make sure ARC does not release and deallocate the object while we are working with it. This kind of bridging cast retains the object so to prevent leaks it must be followed with a corresponding CFRelease somewhere. SecItemCopyMatching definitely..

Weak and strong property setter attributes in Objective-C

http://stackoverflow.com/questions/7912555/weak-and-strong-property-setter-attributes-in-objective-c

the release for you. The only time you would want to use weak is if you wanted to avoid retain cycles e.g. the parent retains the child and the child retains the parent so neither is ever released . The 'toll free bridging' part casting from NS to.. you would want to use weak is if you wanted to avoid retain cycles e.g. the parent retains the child and the child retains the parent so neither is ever released . The 'toll free bridging' part casting from NS to CF is a little tricky. You still..

Retain Cycles: Why is that such a bad thing?

http://stackoverflow.com/questions/791322/retain-cycles-why-is-that-such-a-bad-thing

Cycles Why is that such a bad thing There are two Objects A and B. A creates B and retains it. B has an instance variable that points to A retaining it. So both retain eachother. Some people say that this strong..

When to use properties in objective C?

http://stackoverflow.com/questions/8194281/when-to-use-properties-in-objective-c

use self.propertyName xxx notation for setting and self.propertyName nil for releasing in dealloc . Yes you can do the retains and releases manually but it's a hair tedious to do so and you tend to muck things up when you make quick edits . The one..

Memory management and performSelectorInBackground:

http://stackoverflow.com/questions/873200/memory-management-and-performselectorinbackground

objective c iphone cocoa touch share improve this question First is wrong. performSelectorInBackground withObject retains both bar and foo until task is performed. Thus you should autorelease foo when you create it and let performSelectorInBackground..

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

code. It is easier than your old code. It is not garbage collection. It has no GC runtime cost. The compiler inserts retains and releases in all the places you should have anyway. But it's smarter than you and can optimize out the ones that aren't..

Possible to pass [self anyFunction] in blocks without __weak object (iOS 5 + ARC)

http://stackoverflow.com/questions/9003600/possible-to-pass-self-anyfunction-in-blocks-without-weak-object-ios-5-arc

^ self doSomething Will raise a warning but self performBlock ^ object doSomething No problem here Because an object retains its blocks and a block retains it's objects. So in both these cases the object which performs the block owns the block which.. a warning but self performBlock ^ object doSomething No problem here Because an object retains its blocks and a block retains it's objects. So in both these cases the object which performs the block owns the block which also owns the object. So you..

Does UIView's addSubview really retain the view?

http://stackoverflow.com/questions/937767/does-uiviews-addsubview-really-retain-the-view

not need them as we would know precisely when these events occur. Moreover adding a subview as you said does indeed retains the view. It does NOT however retain the view controller or the navigation controller. Since the navigation controller WILL..