如果你正在处理TypeScript 4.1+和字符串enum，并且你想要一个简单的具有编译时和运行时安全的字符串到enum转换器，下面的工作很好:

export const asEnum = <
  T extends { [key: string]: string },
  K extends keyof T & string
>(
  enumObject: T,
  value: `${T[K]}`
): T[K] => {
  if (Object.values(enumObject).includes(value)) {
    return (value as unknown) as T[K];
  } else {
    throw new Error('Value provided was not found in Enum');
  }
};

enum Test {
  hey = 'HEY',
}

const test1 = asEnum(Test, 'HEY');   // no complaints here
const test2 = asEnum(Test, 'HE');    // compile-time error
const test3 = asEnum(Test, 'HE' as any); // run-time error

Typescript 3.9提案

enum Color{ RED, GREEN }

const color = 'RED' as Color;

容易peasy……柠檬捏的!

对于Typescript >= 4，此代码工作:

enum Color{
    Red, Green
}

// Conversion :
var green= "Green";
var color : Color = green as unknown as Color; 

如果你正在处理TypeScript 4.1+和字符串enum，并且你想要一个简单的具有编译时和运行时安全的字符串到enum转换器，下面的工作很好:

export const asEnum = <
  T extends { [key: string]: string },
  K extends keyof T & string
>(
  enumObject: T,
  value: `${T[K]}`
): T[K] => {
  if (Object.values(enumObject).includes(value)) {
    return (value as unknown) as T[K];
  } else {
    throw new Error('Value provided was not found in Enum');
  }
};

enum Test {
  hey = 'HEY',
}

const test1 = asEnum(Test, 'HEY');   // no complaints here
const test2 = asEnum(Test, 'HE');    // compile-time error
const test3 = asEnum(Test, 'HE' as any); // run-time error

从Typescript 2.1开始，enum中的字符串键都是强类型的。Keyof typeof用于获取可用字符串键的信息(1):

enum Color{
    Red, Green
}

let typedColor: Color = Color.Green;
let typedColorString: keyof typeof Color = "Green";

// Error "Black is not assignable ..." (indexing using Color["Black"] will return undefined runtime)
typedColorString = "Black";

// Error "Type 'string' is not assignable ..." (indexing works runtime)
let letColorString = "Red";
typedColorString = letColorString;

// Works fine
typedColorString = "Red";

// Works fine
const constColorString = "Red";
typedColorString = constColorString

// Works fine (thanks @SergeyT)
let letColorString = "Red";
typedColorString = letColorString as keyof typeof Color;

typedColor = Color[typedColorString];

https://www.typescriptlang.org/docs/handbook/advanced-types.html#index-types

假设你使用typescript: 上面的许多解决方案可能不起作用或过于复杂。

情况:字符串与enum值不相同(大小写不同)

enum Color {
  Green = "green",
  Red = "red"
}

只使用:

const color = "green" as Color

请注意，这并不能保证一个有效的enum。