Swift-如何使协议既是类又需要采用某种类型

Question

I am trying to make protocol that need to have certain type using Self == MyCustomClass . But this protocol is used as delegate type and weak constraint requires it to be also class-only protocol with P rotocolName : class

I have tried something like this

protocol MusicPlayerViewDelegate : class where Self == MusicPlayerController {
}

and then:

weak var delegate : MusicPlayerViewDelegate?

Answer 1

Your protocol needs to extends NSObjectProtocol to be able to use weak with it. You can also try to make MusicPlayerController extend NSObject but I'm not sure it will work.