如何在打字稿中为数字枚举提供替代字符串定义

How to have alternative string definition for numeric enum in typescript

我有一个如下所示的数字枚举。

enum Rating {
  Unknown = 0,
  One,
  Two,
  Three,
  Four
}

当我像下面这样访问枚举字符串时,我需要获取枚举的替代字符串值。

var stringVal = Rating[Rating.One];

上面一行应该给我 "Rating of One" 而不是 One。

我需要坚持使用数字枚举,不能使用字符串枚举。一旦解决方案,我能想到的就是使用如下所示的字符串数组。

const stringRating = ["Unknown Rating", "Rating One", "Rating is Two", "Rating is Three", "Rating is Four"];
export function toString(rating: Rating): string {
return stringValues[rating];

但是在打字稿中有没有更好的方法来实现这一点?

我期待像下面这样的枚举的 c# 中的 Description 属性

public enum MyEnum 
{ 
  [Description("value 1")] 
  Value1, 
  [Description("value 2")]
  Value2, 
  [Description("value 3")]
  Value3
}

您可以将枚举字符串存储在 Map 对象中:

ratingStrings = new Map<Rating,string>([
  [Rating.Unknown, "Unknown Rating"],
  [Rating.One, "Rating One"],
  [Rating.Two, "Rating is Two"],
  [Rating.Three, "Rating is Three"],
  [Rating.Four, "Rating is Four"],
]);

doSomething() {
  let str = this.ratingStrings.get(Rating.Unknown);
  ...
}

或者,如果所有枚举值的字符串格式都相同,您可以使用如下函数:

ratingToString(rating: Rating): string {
  return `Rating ${Rating[rating]}`;
}

doSomething() {
  let str = this.ratingToString(Rating.Unknown);
  ...
}

有关这两种技术的演示,请参阅 this stackblitz