这条线 self = self 迅速做什么

Question

有人可以向我解释一下这段代码中 self = self 的目的是什么吗？

// Keep the reference to the interface :
private var guidedItfRef: Ref<GuidedPilotingItf>?
private var goUp: Bool
...
guidedItfRef = provider.getPilotingItf(PilotingItfs.guided) { [weak self] guidedItf in
    if let guidedItf = guidedItf, let self = self, guidedItf.currentDirective == nil {
        self.goUp = !self.goUp
        guidedItf.moveToRelativePosition(forwardComponent: 0, rightComponent: 0,
                downwardComponent: self.goUp ? 2.0 : -3.0 , headingRotation: 0)
    }
}

Answer 1

当你在闭包中使用[weak self] 时，这将使self 成为可选的，因此你需要用let 解开它

, let self = self // rhs self is optional , `self` or let strongSelf = self

喜欢

var value:int?

解开选项 1

guard let value = value else { return } 
// use value which now is Int not int?

解开选项 2

if let value = value {  
   // use value which now is Int not int?
}