我有一个这样定义的枚举:

export enum GoalProgressMeasurements {
    Percentage = 1,
    Numeric_Target = 2,
    Completed_Tasks = 3,
    Average_Milestone_Progress = 4,
    Not_Measured = 5
}

然而,我希望它被表示为一个对象数组/列表从我们的API如下:

[{id: 1, name: 'Percentage'}, 
 {id: 2, name: 'Numeric Target'},
 {id: 3, name: 'Completed Tasks'},
 {id: 4, name: 'Average Milestone Progress'},
 {id: 5, name: 'Not Measured'}]

是否有简单和本地的方法来做到这一点,或者我必须构建一个函数,将枚举转换为int和字符串,并将对象构建为数组?


当前回答

我很惊讶,在一个TypeScript线程中,没有人给出支持类型的有效TypeScript函数。下面是@user8363解决方案的变化:

const isStringNumber = (value: string) => isNaN(Number(value)) === false;

function enumToArray<T extends {}>(givenEnum: T) {
  return (Object.keys(givenEnum).filter(isStringNumber) as (keyof T)[]).map(
    (key) => givenEnum[key]
  );
}

其他回答

枚举是运行时存在的真实对象。所以你可以这样反向映射:

let value = GoalProgressMeasurements.Not_Measured;
console.log(GoalProgressMeasurements[value]);
// => Not_Measured

基于此,您可以使用以下代码:

export enum GoalProgressMeasurements {
    Percentage = 1,
    Numeric_Target = 2,
    Completed_Tasks = 3,
    Average_Milestone_Progress = 4,
    Not_Measured = 5
}

let map: {id: number; name: string}[] = [];

for(var n in GoalProgressMeasurements) {
    if (typeof GoalProgressMeasurements[n] === 'number') {
        map.push({id: <any>GoalProgressMeasurements[n], name: n});
    }
}

console.log(map);

参考:https://www.typescriptlang.org/docs/handbook/enums.html

function enumKeys(_enum) {
  const entries = Object.entries(_enum).filter(e => !isNaN(Number(e[0])));
  if (!entries.length) {
    // enum has string values so we can use Object.keys
    return Object.keys(_enum);
  }
  return entries.map(e => e[1]);
}

我已经解出来了。 假设您有一个如下所示的枚举

export enum UnitEnum {
  GRAM = 'gm',
  KILOGRAM = 'kg',
  LITRE = 'lt',
  CENTIMETER = 'cm',
  INCH = 'in',
  METER = 'mt',
  KILOMETER = 'km',
}

你有这样一门课,

export interface Unit {
  Name: string;
  Symbol: string;
}

然后,您可以创建一个如下所示的函数,将异构枚举映射到某个类型的对象,

export function getDefaultUnits() {
  const myUnits = Object.entries(UnitEnum).map(x => {
    return { Name: x[0], Symbol: x[1] } as Unit
  })

  console.log(myUnits);

  return myUnits;
}

简单的解决方案。您可以使用以下函数将Enum转换为对象数组。

 buildGoalProgressMeasurementsArray(): Object[] {

    return Object.keys(GoalProgressMeasurements)
              .map(key => ({ id: GoalProgressMeasurements[key], name: key }))
 }

如果你需要去掉下划线,我们可以像下面这样使用regex:

buildGoalProgressMeasurementsArray(): Object[] {

    return Object.keys(GoalProgressMeasurements)
              .map(key => ({ id: GoalProgressMeasurements[key], name: key.replace(/_/g, ' ') }))
 }

首先,我们得到这个枚举的键数组。然后,使用map()函数将数据转换为所需的格式。Id从键获取,name从enum通过相同的键获取。

const converted = Object.keys(GoalProgressMeasurements).map(key => {
        return {
            id: GoalProgressMeasurements[key],
            name: key,
        };
    });