我想迭代一个TypeScript枚举对象,并获得每个枚举符号名称,例如: enum myEnum {entry1, entry2}

for (var entry in myEnum) { 
    // use entry's name here, e.g., "entry1"
}

当前回答

假设您坚持使用规则,只生成带有数值的枚举,您可以使用这段代码。这正确地处理了名称恰好是有效数字的情况

enum Color {
    Red,
    Green,
    Blue,
    "10" // wat
}

var names: string[] = [];
for(var n in Color) {
    if(typeof Color[n] === 'number') names.push(n);
}
console.log(names); // ['Red', 'Green', 'Blue', '10']

其他回答

唯一的解决方案,适用于我在所有情况下(即使值是字符串)是以下:

var enumToString = function(enumType, enumValue) {
    for (var enumMember in enumType) {
        if (enumType[enumMember]==enumValue) return enumMember
    }
}

Typescript游乐场示例

enum TransactionStatus {
  SUBMITTED = 'submitted',
  APPROVED = 'approved',
  PAID = 'paid',
  CANCELLED = 'cancelled',
  DECLINED = 'declined',
  PROCESSING = 'processing',
}


let set1 = Object.entries(TransactionStatus).filter(([,value]) => value === TransactionStatus.SUBMITTED || value === TransactionStatus.CANCELLED).map(([key,]) => {
    return key
})


let set2 = Object.entries(TransactionStatus).filter(([,value]) => value === TransactionStatus.PAID || value === TransactionStatus.APPROVED).map(([key,]) => {
    return key
})

let allKeys = Object.keys(TransactionStatus)



console.log({set1,set2,allKeys})

当我遇到同样的问题时,你可以使用我写的enum-values包:

Git: enum-values

var names = EnumValues.getNames(myEnum);

我的Enum是这样的:

export enum UserSorting {
    SortByFullName = "Sort by FullName", 
    SortByLastname = "Sort by Lastame", 
    SortByEmail = "Sort by Email", 
    SortByRoleName = "Sort by Role", 
    SortByCreatedAt = "Sort by Creation date", 
    SortByCreatedBy = "Sort by Author", 
    SortByUpdatedAt = "Sort by Edit date", 
    SortByUpdatedBy = "Sort by Editor", 
}

这样做会返回undefined:

UserSorting[UserSorting.SortByUpdatedAt]

为了解决这个问题,我选择了另一种使用管道的方法:

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
    name: 'enumKey'
})
export class EnumKeyPipe implements PipeTransform {

  transform(value, args: string[] = null): any {
    let enumValue = args[0];
    var keys = Object.keys(value);
    var values = Object.values(value);
    for (var i = 0; i < keys.length; i++) {
      if (values[i] == enumValue) {
        return keys[i];
      }
    }
    return null;
    }
}

要使用它:

return this.enumKeyPipe.transform(UserSorting, [UserSorting.SortByUpdatedAt]);

可以是简短的:

enum AnimalEnum {
  DOG = "dog", 
  CAT = "cat", 
  MOUSE = "mouse"
}

Object.keys(AnimalEnum).filter(v => typeof v == 'string' && isNaN(v))