UIPopovercontroller dealloc reached while popover is still visible

Question

I assure you that I did look for an answer in SO for my question but none of them were helpful. Here I got a simple code that should present a UIImagePickerController within a UIPopoverController:

-(void)takePicture:(id)sender{
UIImagePickerController *picker=[[UIImagePickerController alloc] init];
picker.delegate=self;
picker.sourceType=UIImagePickerControllerSourceTypeCamera;
picker.allowsEditing=YES;
UIPopoverController *poc=[[UIPopoverController alloc] 
                            initWithContentViewController:picker];
[poc presentPopoverFromBarButtonItem:bbItem 
            permittedArrowDirections:UIPopoverArrowDirectionAny
                            animated:NO];
}

Now, even from the first time I get [UIPopoveController dealloc] reached while... error and the program crashes. I'm not doing any retain,relase or autoreleases as per ARC. Is there any special consideration with UIPopoverControllers when benefitting from ARC?

Solution 1

UIPopoverControllers should always be held in an instance variable. It is a good practice to create a strong property for it.

UPDATE:

As of iOS 8 you should be using UIPopoverPresentationController. Then you don't need to keep a reference to the popover because it is managed by the presentation controller.

Code example (works both on iPhone and iPad):

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.allowsEditing = YES;
picker.modalPresentationStyle = UIModalPresentationPopover;
UIPopoverPresentationController* popoverPC = picker.popoverPresentationController;
popoverPC.barButtonItem = bbItem;
popoverPC.permittedArrowDirections = UIPopoverArrowDirectionAny;
[self presentViewController:picker animated:YES completion:nil];

Solution 2

When the function exits there are no other reference to the popover controller, so it's deallocated too early.

Try adding it as a member of your class instead.

Tim

Solution 3

Adding what @phix23 answered, create *poc property like this:

@property (nonatomic, retain) IBOutlet UIPopoverController *poc;

and then change

UIPopoverController *poc = [[UIPopoverController alloc] 
                            initWithContentViewController:picker];

for

self.poc = [[UIPopoverController alloc] 
                            initWithContentViewController:picker];

Comments

[Mikayil Abdullayev]

Oh, I see. But isn't this like a UIAlertView? I never have an ivar for it, I just alloc init it wherever I need, show it and then [used to] release. In what is popovercontroller different?

[Mikayil Abdullayev]

Shouldn't I still be able to see it first before it gets deallocated?

[fzwo]

@Mikayil The alertView is retained by its superview (as all views are), but the popoverController isn't a view, so doesn't have a superview, so won't be retained by anybody if you don't retain it (or store it in a strong variable that has a scope that's longer than the current method - for instance an iVar).

[Mikayil Abdullayev]

But I'm still confused about the retain count of the UIPopoverController. Because I put a check before I alloc and init one. And only if it's nil I alloc a new one. But after allocating it for the first time I never get it nil. I mean I call a method once. There I allocate and init my ivar. And the next time when I again call that method this time I find my ivar already allocated. If ARC takes care of this, then when does it release it. Or does it autorelease it?

[Felix]

@Mikayil ivars are released by ARC when the object is deallocated or when you set them to nil

[Joshua Dance]

You don't have to put it in your .h file. That would make it public and unless you want that, just make it a property in your .m file.

[Amit Battan]

but they have not mention this in the documentation, in How to Use section they use local variable