如何在Kotlin中从字符串创建枚举? [英] How do I create an enum from a string in Kotlin?

问题描述

我有一个带有某些实例Foo和Bar的枚举.如果我有字符串"Foo"，如何从中实例化Foo枚举?在C#中将为Enum.Parse(...)，在Kotlin中是否具有等效项?

I have an enum with some instances Foo and Bar. If I have a string "Foo", how can I instantiate a Foo enum from that? In C# it would be Enum.Parse(...), is there an equivalent in Kotlin?

目前，我发现的最好的方法是创建一个工厂，该工厂可以打开所有可能的字符串，但这容易出错，并且对于较大的枚举而言效果不佳.

Currently, the best I have found is to create a factory that switches on all possible strings, but that is error prone and performs poorly for large enumerations.

推荐答案

Kotlin枚举类具有静态"功能valueOf以按字符串获取枚举条目(例如Java枚举).另外，它们具有静态"功能values以获取所有枚举条目.示例:

Kotlin enum classes have "static" function valueOf to get enum entry by string(like Java enums). Additionally they have "static" function values to get all enum entries. Example:

enum class MyEnum {
  Foo, Bar, Baz
}

fun main(args : Array<String>) {
  println(MyEnum.valueOf("Foo") == MyEnum.Foo)
  println(MyEnum.valueOf("Bar") == MyEnum.Bar)
  println(MyEnum.values().toList())
}

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