Xcode 8 beta 6:AnyObject被Any替换:哪里是classForCoder？

Question

xcode的8个β6取代AnyObject通过Any.

在某些情况下,我用于a.classForCoder调试原因,看看它里面有什么.有了AnyObject这个工作.有了Any这不起作用了.

现在我必须使用Any:在类型变量中查看哪种类型的首选方法是什么Any？

转换AnyObject似乎不是非常有用,因为在许多情况下这是一个String并且自Xcode 8 beta 6以后String不再确认AnyObject.

Answer 1

使用类型(:)

您可以使用type(of:)查找变量类型中的变量类型Any.

let a: Any = "hello"
print(type(of: a))  // String

let b: Any = 3.14
print(type(of: b))  // Double

import Foundation
let c: Any = "hello" as NSString
print(type(of: c))  // __NSCFString

let d: Any = ["one": 1, "two": "two"]
print(type(of: d))  //  Dictionary<String, Any>

struct Person { var name = "Bill" }
let e: Any = Person()
print(type(of: e))  // Person

使用classForCoder

classForCoder仍然存在,并且您可以将类型的值转换Any为AnyObject,但如果该值是Swift值类型,您将获得转换结果而不是原始类型:

import Foundation // or import UIKit or import Cocoa

let f: Any = "bye"
print((f as AnyObject).classForCoder)  // NSString
print(type(of: f))                     // String

let g: Any = 2
print((g as AnyObject).classForCoder)  // NSNumber
print(type(of: g))                     // Int

let h: Any = [1: "one", 2: 2.0]
print((h as AnyObject).classForCoder)  // NSDictionary
print(type(of: h))                     // Dictionary<Int, Any>

struct Dog { var name = "Orion" }
let i: Any = Dog()
print((i as AnyObject).classForCoder)  // _SwiftValue
print(type(of: i))                     // Dog

// For an object, the result is the same
let j: Any = UIButton()
print((j as AnyObject).classForCoder)  // UIButton
print(type(of: j))                     // UIButton