鉴于此模型: public class RSS2Feed { public var channel: RSS2FeedChannel? public init() {}}public class RSS2FeedChannel { public var title: String? public var description: String? public init() {}} 为了获取RSS2FeedChannel实例的属
public class RSS2Feed {
public var channel: RSS2FeedChannel?
public init() {}
}
public class RSS2FeedChannel {
public var title: String?
public var description: String?
public init() {}
}
为了获取RSS2FeedChannel实例的属性名称和值,我需要做什么?
这是我正在尝试的:
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
}
最后,我正在尝试创建一个匹配实例的Dictionary,使用反射,但到目前为止,我无法获取实例的属性名称和值.
文档说:
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.
然而,我只得到一个“一些”字符串.
此外,当我希望每个子节点都是“反射实例结构的元素”时,value属性返回一个带有类型RSS2FeedChannel的字符串.
当我理解正确这应该解决你的问题: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
}
只是swift 3的一些小变化:
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
}
