相关疑难解决方法(0)

我正在使用ARC专门为iOS 5开发.应该IBOutlets UIView(和子类)是strong或weak？

下列:

@property (nonatomic, weak) IBOutlet UIButton *button;

将摆脱所有这一切:

- (void)viewDidUnload
{
    // ...
    self.button = nil;
    // ...
}

这样做有什么问题吗？模板正在使用strong,当从"Interface Builder"编辑器直接连接到标题时创建的自动生成属性,但为什么？在UIViewController已经有一个strong到其基准view保留其子视图.

I have created a class called VerifyObject, that contains a function with a signature like that

typealias handlerCodeID = (String) ->Void

class func checkPause(withID:String?,
  runOnPause: handlerCodeID?) 

When I run that, I need to pass a weak self reference to inside the closure, using

VerifyObject.checkPause(withID: "abcde", 
  runOnPause: {[weak self] (objectID) in
    self.doSomething()
})

Xcode complains that the self in doSomething must be unwrapped to

self!.doSomething()

why? Does not make sense.