提供的大多数答案都没有对Enums提供广泛的支持。允许OP请求只从字符串值中获取Enum，但是Enum也允许其他值。

interface StandardEnum<T> {
    [id: string]: T | string;
    [nu: number]: string;
}

/**
 * Converts the given representation of the value of one enumerated constant to an equivalent enumerated type.
 *
 * @param type - An enumeration type
 * @param value - A value to convert
 */
export const genericValueToEnum = <T, K extends StandardEnum<T>> (
    type: StandardEnum<T>,
    value: K[keyof K]
): T | undefined => {
    const keys = Object.keys(type); // ...but, not really.
    const values = Object.values(type)
        // Filter enum member names because `Object.values()` includes them.
        .filter((value) => !(
            typeof value === 'string' &&
            keys.includes(value) &&
            type[value] !== value
        ));

    return values.includes(value)
        ? value as unknown as T
        : undefined;
}

这将适用于所有枚举，无论它们多么复杂(或奇怪)，只要它们没有被标记。

enum OddEnum {
    None = -1,
    No = 0,
    Yes = 1,
    Twenty = '20'
    Other = 'Other',
    MORE = 'More',
};

genericValueToEnum(OddEnum, -1); // => -1 as OddEnum;
genericValueToEnum(OddEnum, 'Other'); // => 'Other' as OddEnum;
genericValueToEnum(OddEnum, 'MORE'); // => undefined;

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

其他的变化可以是

const green= "Green";

const color : Color = Color[green] as Color;

如果您为枚举提供字符串值，则直接强制转换可以很好地工作。

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

const color = "Green";
const colorEnum = color as Color;

如果您正在使用名称空间来扩展枚举的功能，那么您还可以这样做

    enum Color {
        Red, Green
    }

    export namespace Color {
      export function getInstance(color: string) : Color {
        if(color == 'Red') {
          return Color.Red;
        } else if (color == 'Green') {
          return Color.Green;
        }
      }
    }

像这样使用它

  Color.getInstance('Red');

它在TypeScript 4.4.3 TS游乐场链接中为我工作。

  const stringToEnumValue = <T extends Record<string, string>, K extends keyof T>(
    enumObj: T,
    value: string,
  ): T[keyof T] | undefined =>
    enumObj[
      Object.keys(enumObj).filter(
        (k) => enumObj[k as K].toString() === value,
      )[0] as keyof typeof enumObj
    ];

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

  const result1 = stringToEnumValue(Color, 'yellow'); // undefined
  const result2 = stringToEnumValue(Color, 'green'); // Color.Green

  console.log(result1) // undefined = undefined
  console.log(result2) // Color.Green = "green"