将保留对象分配给弱属性;对象将分配

Question

后公布我使用的一些源代码：

KGModalContainerView *containerView = 
    self.containerView = 
     [[KGModalContainerView alloc] initWithFrame:containerViewRect]; 

它给我：Assigning retained object to weak property; object will be released after assignment

编辑：

@interface KGModal() 
    @property (strong, nonatomic) UIWindow *window; 
    @property (weak, nonatomic) KGModalViewController *viewController; 
    @property (weak, nonatomic) KGModalContainerView *containerView; 
    @property (weak, nonatomic) UIView *contentView; 
@end 

KGModalContainerView *containerView = 
    self.containerView = 
     [[KGModalContainerView alloc] initWithFrame:containerViewRect]; 
containerView.modalBackgroundColor = self.modalBackgroundColor; 
containerView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | 
           UIViewAutoresizingFlexibleRightMargin | 
           UIViewAutoresizingFlexibleTopMargin | 
           UIViewAutoresizingFlexibleBottomMargin; 
containerView.layer.rasterizationScale = [[UIScreen mainScreen] scale]; 
contentView.frame = (CGRect){padding, padding, contentView.bounds.size}; 
[containerView addSubview:contentView]; 
[viewController.view addSubview:containerView]; 

Answer 1

我想你containerView财产申报与weak属性。如果你想拥有一个weak属性给一个人应该已经保留它的财产。下面是一个例子：

@property (nonatomic, weak) KGModalContainerView *containerView; 
... 
-(void)viewDidLoad { 
    [super viewDidLoad]; 
    KGModalContainerView *myContainerView = [[KGModalContainerView alloc] initWithFrame:containerViewRect]; // This is a strong reference to that view 
    [self.view addSubview:myContainerView]; //Here self.view retains myContainerView 
    self.containerView = myContainerView; // Now self.containerView has weak reference to that view, but if your self.view removes this view, self.containerView will automatically go to nil. 

// In the end ARC will release myContainerView, but it's retained by self.view and weak referenced by self.containerView 
} 

Answer 2

我2美分作为目标C初学者：

给出警告的线的右侧，

[[KGModalContainerView alloc] initWithFrame:containerViewRect] 

在堆中创建一个对象此时此对象不被任何指针引用。然后将此对象分配给self.containerView。由于self.myContainerView较弱，因此该赋值不会增加右侧创建的对象的引用计数。因此，当分配完成后，对象的引用计数仍为0，因此ARC会立即释放该对象。