swift - 反射(reflection):在Swift中获取类的静态var？

Question

给出一个简单的类，比如：

class Foo {
    static var can: String? { didSet { 5+4 } }
    static let haz: String
}

如何在 Foo中实现枚举 can和 haz的方法，而不必再次显式地写出它们？-例如：这样我就可以 print("key: '\(key\)' has value: '\(value)'")
顺便说一句：注意到这一点： How to loop over struct properties in Swift?；但无法让它为 static工作。

Answer 1

您可以使用Objective-c运行时，特别是描述类声明的属性的函数class_copyPropertyList。例子：

import Foundation

class Foo:NSObject {
    @objc static var prop1: String? = "Hello I am prop1!"
    @objc static var prop2: String? = "Hello I am prop2!"
}

var count: CUnsignedInt = 0
let methods = class_copyPropertyList(object_getClass(Foo.self), &count)!
for i in 0 ..< count {
    let selector = property_getName(methods.advanced(by: Int(i)).pointee)
    if let key = String(cString: selector, encoding: .utf8) {
        let res = Foo.value(forKey: key)
        print("name: \(key), value: \(res ?? "")")
    }
}