iphone - 将保留对象分配给弱属性；分配后对象将被释放

Answer 1

我想你的containerView财产是用weak属性声明的。如果您想拥有某个weak属性的属性，那么应该已经有人保留了它。这是一个例子：

@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

我作为 Objective C 初学者的 2 美分：

给出警告的行的右侧，

[[KGModalContainerView alloc] initWithFrame:containerViewRect]

在堆中创建一个对象，此时该对象没有被任何指针引用。然后将此对象分配给self.containerView。因为self.myContainerView是弱的，所以赋值不会增加右侧创建的对象的引用计数。所以当赋值完成后，对象的引用计数还是0，因此ARC会立即释放对象。