Swift - 具有类型和协议的属性 [英] Swift - Property with type and protocol

问题描述

在我的一个 Objective-C 类中，我有一个 UIViewController 类型的属性，我将如何在 Swift 中表示它?我需要从 UIViewController 和 UIProfileListHeaderDelegate 访问属性和方法.

In one of my Objective-C clases, I have a property of type UIViewController<UIProfileListHeaderDelegate>, how would I represent this in Swift? I need to access properties and methods from both UIViewController and UIProfileListHeaderDelegate.

谢谢！

推荐答案

处理这个问题的快速方法是定义一个协议，其中包含来自 UIViewController 的相关方法，并让您的 UIProfileListHeaderDelegate 继承自那个.

The swift way to handle this is to define a protocol that includes the relevant methods from UIViewController and have your UIProfileListHeaderDelegate inherit from that.

用你关心的方法定义一个协议:

Define a protocol with the methods you care about:

protocol ViewControllerSubset {
    var view:UIView!
}

声明 UIViewController 实现了协议，不需要实际实现任何东西，因为它已经存在了

Declare that UIViewController implements the protocol, don't need to actually implement anything because it's already there

extension UIViewController : ViewControllerSubset {}

继承你的协议

protocol UIProfileListHeaderDelegate : ViewControllerSubset

你走吧.

如果你不想改变你的协议的层次结构(或者不能因为它是一个系统协议)你可以定义一个包含两个协议的协议)

If you don't want to change the hierarchy of your protocol (or can't because it's a system protocol) you can define a protocol that contains both protocols)

protocol EquatableAndComparable : Equatable, Comparable { }

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