如何使用Swift 2.0和反射获取属性名称及其值?

本文介绍了如何使用Swift 2.0和反射获取属性名称及其值?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

给出此模型:

public class RSS2Feed { public var channel: RSS2FeedChannel? public init() {} } public class RSS2FeedChannel { public var title: String? public var description: String? public init() {} }

我需要做什么才能获取RSS2FeedChannel实例的属性名称和值?

What would I need to do in order to get the property names and values of an RSS2FeedChannel instance?

这就是我要尝试的:

let feed = RSS2Feed() feed.channel = RSS2FeedChannel() feed.channel?.title = "The Channel Title" let mirror = Mirror(reflecting: feed.channel) mirror.children.first // ({Some "Some"}, {{Some "The Channel Title... for (index, value) in mirror.children.enumerate() { index // 0 value.label // "Some" value.value // RSS2FeedChannel }

最终，我正在尝试使用反射创建一个与实例匹配的Dictionary，但是到目前为止，我无法获得实例的属性名称和值.

Ultimately, I'm trying to create a Dictionary that matches the instance, using reflection, but so far I'm unable to get the properties name and values of the instance.

文档说:

在适当的时候可以使用可选标签，例如表示存储属性或活动枚举大小写的名称，当将字符串传递给后代方法时将用于查找.

The optional label may be used when appropriate, e.g. to represent the name of a stored property or of an active enum case, and will be used for lookup when Strings are passed to the descendant method.

但是我只得到一个"Some"字符串.

Yet I only get a "Some" string.

此外，当我希望每个子对象都是反映实例结构的元素"时，value属性将返回类型为RSS2FeedChannel的字符串！

Also, the value property is returning a string with the Type RSS2FeedChannel when I would expect each children to be "An element of the reflected instance's structure."!

推荐答案

当我理解正确时，这应该可以解决您的问题:

When i understand correct this should solve ur problem:

func aMethod() -> Void { let feed = RSS2Feed() feed.channel = RSS2FeedChannel() feed.channel?.title = "The Channel Title" // feed.channel?.description = "the description of your channel" guard let channel = feed.channel else { return } let mirror = Mirror(reflecting: channel) for child in mirror.children { guard let key = child.label else { continue } let value = child.value guard let result = self.unwrap(value) else { continue } print("\(key): \(result)") } } private func unwrap(subject: Any) -> Any? { var value: Any? let mirrored = Mirror(reflecting:subject) if mirrored.displayStyle != .Optional { value = subject } else if let firstChild = mirrored.children.first { value = firstChild.value } return value }

快速3进行一些小的更改，

just some little changes for swift 3:

private func unwrap(_ subject: Any) -> Any? { var value: Any? let mirrored = Mirror(reflecting:subject) if mirrored.displayStyle != .optional { value = subject } else if let firstChild = mirrored.children.first { value = firstChild.value } return value }