swift - 使用从父类(super class)继承的值创建字典

Question

我有多个类继承自单个类，是否可以为它们创建字典映射？这样我就可以在给定字符串键的情况下引用正确的类。

let map = [String: EngineView] = [
  "google": GoogleView,
  "duckduckgo": DuckDuckGoView
]

GoogleView 和 DuckDuckGoView 都是 EngineView 的子类，但 XCode 提示:

“无法将“GoogleView.Type”类型的值转换为预期的字典值类型“EngineView””

Answer 1

假设 GoogleView 和 DuckDuckGoView 继承自 EngineView 你可以这样做:

let map = [String: EngineView.Type] = [
  "google": GoogleView.self,
  "duckduckgo": DuckDuckGoView.self
]

使用

if let aClass = map["google"] {
    let instance = aClass.init()
}