automatic-ref-counting

问题 my project use ARC , and when i have to show a view with navigation controller i do this: ShareViewController_iPhone *share = [[ShareViewController_iPhone alloc] initWithNibName:@"ShareViewController_iPhone" bundle:nil]; [self.navigationController pushViewController:share animated:YES]; and i can see in xcode that the memory is increased of a certain value, then when i dismiss the view i do this: [self.navigationController popViewControllerAnimated:YES]; but when the view is closed, the

问题 I have a class called Location with the following automatically generated declaration, #import <Foundation/Foundation.h> #import <CoreData/CoreData.h> @interface Location : NSManagedObject @property (nonatomic, retain) NSNumber * cosRadLat; @property (nonatomic, retain) NSNumber * latitude; @property (nonatomic, retain) NSNumber * longitude; @property (nonatomic, retain) NSNumber * radLat; @property (nonatomic, retain) NSNumber * radLng; @property (nonatomic, retain) NSNumber * sinRadLat;

问题 I have some doubts with the ARC. In ARC: When a viewcontroller is dismissed by using the dismissViewController/popViewController, Will it's allocated memory automatically get released? What will happen when there is an asynchronous NSURLConnection is running and before that operation completed, viewcontroller got dismissed? Thank you 回答1: When you dismiss a view controller (or pop it), it will be deallocated if you didn't make any strong pointers to it (that controller is retained by the

问题 I am new to ARC and I have been playing with it for less than a week. What I am trying to do is very basic. I have a view controller that displays a button. When I click the button, the corresponding selector needs to be called. However, with ARC, the application crashed with an EXC_BAD_ACCESS message. Below is the code from my MainViewController - (void)loadView { [super loadView]; UIButton *testButton=[UIButton buttonWithType:UIButtonTypeRoundedRect]; [testButton setFrame:CGRectMake(80,50

问题 EDIT My problem was that I didn't link a class to my project. I am working on an app that is basically a terminal app. When I try to build it I'm getting a build error. Ld /Users/evanstoddard/Library/Developer/Xcode/DerivedData/Highjack-anstcjvykrnniwbltvijvyvexirq/Build/Products/Debug-iphonesimulator/Highjack.app/Highjack normal i386 cd /Users/evanstoddard/Desktop/Highjack setenv IPHONEOS_DEPLOYMENT_TARGET 6.0 setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator

问题 Is there an iOS 5 arc compatible lazy Image loading library? I've not found one. My next thought is to make EGOlazyloading a compiled library and link it to my project. Would that work? Any pointers on going about? Thanks! 回答1: I wrote one. You can download it here: https://github.com/nicklockwood/AsyncImageView Alternatively, if you do want to use EGO, or some other library, select Edit>Refactor>Convert to ARC and in the dialog that comes up there's a little drop down to select which files

问题 Why is this code running on the simulator and crashing on a real device? I have a very simple code that draws a circle. The code subclasses UIView and runs fine on the Simulator (both for iOS 5.1 and iOS 6.0). Circle.h #import <UIKit/UIKit.h> @interface Circle : UIView @end Circle.m #import "Circle.h" @implementation Circle -(CGPathRef) circlePath{ UIBezierPath *path = [UIBezierPath bezierPath]; [path addArcWithCenter:self.center radius:10.0 startAngle:0.0 endAngle:360.0 clockwise:YES];

问题 I pass a completion block to my method, this completion block will be called in the background when a network request is finished. Unfortunately, if the calling object is deallocated in the meantime, the app crashes: ViewController (which may be deallocated because it's popped from the navigation stack) code: __unsafe_unretained ViewController *weakSelf = self; [[URLRequester instance] sendUrl:url successBlock:^(id JSON) { [weakSelf webserviceCallReturned:JSON]; }]; URLRequester-Code (made

问题 I finally found my memory bug is caused by referring self strongly in a block. But I don't know why in a similar case, the weak is not needed: I have a CameraCaptureManager class doing image capture tasks, and a CameraViewController has a strong property of this manager. The manager has weak delegate property pointing back to the controller. This is where I must use weakSelf in the manager, otherwise -(void)dealloc won't be called: // in CameraCaptureManager __weak CameraCaptureManager

问题 I want to create a similar class to UIAlertView which doesn't require a strong ivar. For example, with UIAlertView, I can do the following in one of my UIViewController's methods: UIAlertView *alertView = [[UIActionSheet alloc] initWithTitle:nil message:@"Foo" delegate:nil cancelButtonTitle:@"Cancel" otherButtonTitles:nil]; [alertView show]; ... and the actionSheet will not be dealloced until it is no longer visible. If I were to try to do the same thing: MYAlertView *myAlertView = [