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

我从几个月前就了解了typescript,下面的解决方案对我来说很有效。希望它也能帮助到一些人

export enum ScheduleType {
  Basic = <any>'B',
  Consolidated = <any>'C',
}

scheduleTypes = Object.keys(ScheduleType)
.filter((k, i) => i % 2)
.map((key: any) => {
  return {
    systemValue: key,
    displayValue: ScheduleType[key],
  };
});

它给出了如下的结果- [{displayValue: "Basic", systemValue: "B"}, {displayValue: "Consolidated", systemValue: "C"}]

其他回答

一个棘手的地方是TypeScript会在触发对象中'double'映射enum,所以它可以通过键和值访问。

enum MyEnum {
    Part1 = 0,
    Part2 = 1
}

将以

{
   Part1: 0,
   Part2: 1,
   0: 'Part1',
   1: 'Part2'
}

所以你应该在映射之前先过滤对象。所以@Diullei的解决方案是正确的。这是我的实现:

// Helper
const StringIsNumber = value => isNaN(Number(value)) === false;

// Turn enum into array
function ToArray(enumme) {
    return Object.keys(enumme)
        .filter(StringIsNumber)
        .map(key => enumme[key]);
}

像这样使用它:

export enum GoalProgressMeasurements {
    Percentage,
    Numeric_Target,
    Completed_Tasks,
    Average_Milestone_Progress,
    Not_Measured
}

console.log(ToArray(GoalProgressMeasurements));
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]);
}

多亏了波尔科夫尼科夫。我终于能够找到一个解决方案,将工作的大多数用例。

问题的有效解

type Descripted<T> = {
    [K in keyof T]: {
        readonly id: T[K];
        readonly description: string;
    }
}[keyof T]

/**
 * Helper to produce an array of enum descriptors.
 * @param enumeration Enumeration object.
 * @param separatorRegex Regex that would catch the separator in your enum key.
 */
export function enumToDescriptedArray<T>(enumeration: T, separatorRegex: RegExp = /_/g): Descripted<T>[] {
    return (Object.keys(enumeration) as Array<keyof T>)
        .filter(key => isNaN(Number(key)))
        .filter(key => typeof enumeration[key] === "number" || typeof enumeration[key] === "string")
        .map(key => ({
            id: enumeration[key],
            description: String(key).replace(separatorRegex, ' '),
        }));
}

例子:


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

console.log(enumToDescriptedArray(GoalProgressMeasurements))
// Produces:
/*
[
    {id: 1, description: "Percentage"},
    {id: 2, description: "Numeric Target"},
    {id: 3, description: "Completed Tasks"},
    {id: 4, description: "Average Milestone Progress"},
    {id: 5, description: "Not Measured"}
]
*/

此外,我还使用了一个有用的util函数来将枚举对象映射到它拥有的可用值数组:

该映射器

type NonFunctional<T> = T extends Function ? never : T;

/**
 * Helper to produce an array of enum values.
 * @param enumeration Enumeration object.
 */
export function enumToArray<T>(enumeration: T): NonFunctional<T[keyof T]>[] {
    return Object.keys(enumeration)
        .filter(key => isNaN(Number(key)))
        .map(key => enumeration[key])
        .filter(val => typeof val === "number" || typeof val === "string");
}

用例工作

数字枚举

enum Colors1 {
    WHITE = 0,
    BLACK = 1
}
console.log(Object.values(Colors1)); // ['WHITE', 'BLACK', 0, 1]
console.log(enumToArray(Colors1));   // [0, 1]

字符串枚举

enum Colors2 {
    WHITE = "white",
    BLACK = "black"
}
console.log(Object.values(Colors2)); // ['white', 'black']
console.log(enumToArray(Colors2));   // ['white', 'black']

异构枚举

enum Colors4 {
    WHITE = "white",
    BLACK = 0
}
console.log(Object.values(Colors4)); // ["BLACK", "white", 0]
console.log(enumToArray(Colors4));   // ["white", 0]

与具有导出函数的命名空间合并的Enum


enum Colors3 {
    WHITE = "white",
    BLACK = "black"
}
namespace Colors3 {
    export function fun() {}
}
console.log(Object.values(Colors3)); // ['white', 'black', Function]
console.log(enumToArray(Colors3));   // ['white', 'black']

enum目标进度测量{ 百分比= 1, Numeric_Target = 2, Completed_Tasks = 3, average_milestone one_progress = 4, Not_Measured = 5 } Const数组= [] for (const [key, value] of Object.entries(GoalProgressMeasurements)) { if (!Number. isnan (Number(key)) { 继续; } 数组中。Push ({id:值,名称:键。Replace ('_', ")}); } console.log(数组);

在数组中获取enum值。

export enum DocumentationTypeEnum {
  GDPR = 'GDPR',
  HELP = 'HELP',
  OTHER = 'OTHER',
  FOOTER = 'FOOTER'
}
const keys = Object.keys(DocumentationTypeEnum);
    
console.log(keys); // Output :  ["GDPR", "HELP", "OTHER", "FOOTER"]