automatic-ref-counting

I have a scrollview that shows different images as it's scrolled through the pages, like PhotoScroller. I'm using ARC. When someone scrolls to another page, I set the image property of the UIImageView not being currently show to nil, as (attempting) to avoid memory crashes, which are still happening. Then when the user scrolls to a new page, the image for that page is set as the UIImageView's image property, as well as the page before and after it (for smooth viewing). The UIImage's for the pages are all held in an array. Yet as I scroll through the pages, memory usage keeps going up, as if

The vague overview is that I'm writing a method in an NSArray Category that will take a Class and filter an Array down to elements that are members of that class. Something like: @implementation NSArray(filter) -(NSArray*)objectsOfClass:(Class)aClass { NSMutableArray *ret = [[NSMutableArray alloc] init]; for (id obj in self) if ([obj isMemberOfClass:aClass]) [ret addObject:obj]; return [NSArray arrayWithArray:ret]; } @end Sooo, with that out of the way, on to my question. NSObject.h shows that isMemberOfClass: has the following signature: -(BOOL)isMemberOfClass:(Class)aClass; When I type this

I am trying to implement a method that executes a task in the background and then calls a block on the main thread: + (void)migrateStoreWithCompletionHandler:(MigrationControllerCompletion)completion { MigrationController *controller = [[MigrationController alloc] initWithCompletionBlock:completion]; [controller migrateStore]; } This is the -initWithCompletionBlock: method: - (id)initWithCompletionBlock:(MigrationControllerCompletion)completion { self = [super init]; if (self) { _completion = [completion copy]; } return self; } The background work happens in -migrateStore . The problem is that

I am using ARC and the app crashes saying received memory warning . I have used the apple instruments: It looks like I do not have any leaks but I cannot find where is wrong. The crash has to do with the memory and due arc I cannot use release and any sort. It is my first time dealing with memory usage using arc. Is there away I can Debug this since I am dealing this for nearly two months. I have my code on my git hub so it will be helpful if you look at it. You can find it here. I am dealing this problem for weeks and want to end this. Thanks. Not all "leaks" show up in the "Leaks" tool in

I haven't seemed to run into a problem yet, but I'm trying to make sure I'm using some best practices. Say I have a UITableViewController with a data source of an NSArray of MyObject objects. So in my UITableViewController I declare my data source like: @property (strong, nonatomic) NSArray *dataSource; Then after I touch a cell I want to push a new view that shows a detail view of something, using that cell's MyObject. So in the new UIViewController I have this: @property (strong, nonatomic) MyObject *myObject; Now in the UITableViewController when a cell is touched: MyObject *myObject = [

Consider this: id observer = [[NSNotificationCenter defaultCenter] addObserverForName:MyNotification object:nil queue:nil usingBlock:^(NSNotification *note) { [[NSNotificationCenter defaultCenter] removeObserver:observer name:MyNotification object:nil ]; // do other stuff here... } ]; I'm using this pattern to observe a notification once and then stop observing it. But LLVM tells me (under ARC) that Variable 'observer' is uninitialized when captured by block. How can I fix this, since the block necessarily captures the variable before initialization, it being part of the initializer? Will

Here, I was playing with leaks, so I've made a strong reference cycle intentionally to see if the Instruments will detect something, and I got unexpected results. The leak shown in Instruments certainly make sense, but the random crash is a bit mysterious (due to two facts I will mention later). What I have here is a class called SomeClass : class SomeClass{ //As you can guess, I will use this shady property to make a strong cycle :) var closure:(()->())? init(){} func method(){} deinit {print("SomeClass deinited")} } Also I have two scenes, the GameScene : class GameScene: SKScene { override