带有空初始化的协议

Question

我使用的框架有一个 'user' 协议，其中列出了所有需要的属性，该协议还有一个空的 init 方法。我需要创建一个用户，但是我使用该协议创建的任何实例都会抱怨 init 没有初始化所有属性

框架协议

public protocol User {

/// Name
public var firstname: String { get set }

/// Lastname
public var lastname: String { get set }

///Init
public init()
}

我如何使用此协议创建自己的结构并在初始化时向参数添加值？

提前致谢！

Answer 1

您可以如下使用：

struct MyAppUser: User {

   // default init coming from protocol
   init() {
       self.firstname = ""
       self.lastname = ""
   }

   // you can use below init if you want
   init(firstName: String, lastName: String) {
       self.firstname = firstName
       self.lastname = lastName
   }

   // coming from protocol
   var firstname: String
   var lastname: String
}

// user 1
var user1 = MyAppUser()
user1.firstname = "Ashis"
user1.lastname = "laha"
print(user1)

// user 2
let user2 = MyAppUser(firstName: "Kunal", lastName: "Pradhan")
print(user2)

输出：

MyAppUser(firstname: "Ashis", lastname: "laha")
MyAppUser(firstname: "Kunal", lastname: "Pradhan")

带有空初始化的协议

Protocol with Empty Init

protocols

swift

protocol-extension

输出：