Login flow failing after upgrading to iOS9

问题:

After upgrading my app to iOS9 I’am getting an error in my app which says:

: objc[344]: Cannot form weak reference to instance (0x15919e00) of class LoginVC. It is possible that this object was over-released, or is in the process of deallocation.

Below is the function in which i get this error:

-(void)dismissLogin { self.isLoggingIn = NO; [self stopLoginAnimation]; [self dismissViewControllerAnimated:YES completion:NO]; [[NSNotificationCenter defaultCenter] removeObserver:self]; [self.appDelegate setLoginVC:nil]; [self.view removeFromSuperview]; //[APPDEL selectTabBar]; } 

The app gets stuck at the login screen and doesn't switch to next screens.

This error doesn’t come in iOS8. Can anyone help me with this issue.

回答1:

Make sure you are not using instance being deallocated.

I have the same issue. It was not occurring in iOS 8 but occurred in iOS 9. Because I was overriding setDelegate method like this.

-(void)setDelegate:(id<UICollectionViewDelegate>)delegate{     _internalDelegate = delegate;     [super setDelegate:self]; } 

So in iOS 9, OS sets delegate to nil on de-allocation, but I was setting it to self. So quick fix was

-(void)setDelegate:(id<UICollectionViewDelegate>)delegate{     _internalDelegate = delegate;     if (delegate) {         //Set delegate to self only if original delegate is not nil         [super setDelegate:self];     }else{         [super setDelegate:delegate];     } } 

回答2:

I ran into this issue recently and this helped me come to the conclusion that I did. The only issue I have with the solution provided above is that if you need the subclass to gain functionality even when its internalDelegate is nil, it just won't work.

Here's the solution I came up with that both prevents the crash and allows functionality to exist even with a nil internalDelegate. Figured I'd share in case anyone else came across this.

1. Create a second internal property, I called this weakSelf

 @property (nonatomic, weak) LoginVC *weakSelf; 

2. Inside any initialization methods, set weakSelf to self

  - (id)init {     if ((self = [super init])) {         self.weakSelf = self;     } } 

3. Update delegate method

 - (void)setDelegate:(id)delegate {     _internalDelegate = delegate;     [super setDelegate:self.weakSelf]; } 

文章来源: Login flow failing after upgrading to iOS9