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

老问题了,为什么不使用const对象映射呢?

不要这样做:

enum Foo {
    BAR = 60,
    EVERYTHING_IS_TERRIBLE = 80
}

console.log(Object.keys(Foo))
// -> ["60", "80", "BAR", "EVERYTHING_IS_TERRIBLE"]
console.log(Object.values(Foo))
// -> ["BAR", "EVERYTHING_IS_TERRIBLE", 60, 80]

这样做(注意as const强制转换):

const Foo = {
    BAR: 60,
    EVERYTHING_IS_TERRIBLE: 80
} as const

console.log(Object.keys(Foo))
// -> ["BAR", "EVERYTHING_IS_TERRIBLE"]
console.log(Object.values(Foo))
// -> [60, 80]

其他回答

基于上面的一些回答,我提出了这个类型安全的函数签名:

export function getStringValuesFromEnum<T>(myEnum: T): (keyof T)[] {
  return Object.keys(myEnum).filter(k => typeof (myEnum as any)[k] === 'number') as any;
}

用法:

enum myEnum { entry1, entry2 };
const stringVals = getStringValuesFromEnum(myEnum);

stringVals的类型是'entry1' | 'entry2'

看看它的实际应用

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]);

简单地说

如果你的枚举如下:

export enum Colors1 {
  Red = 1,
  Green = 2,
  Blue = 3
}

要获得特定的文本和值:

console.log(Colors1.Red); // 1 
console.log(Colors1[Colors1.Red]); // Red

获取值和文本列表:

public getTextAndValues(e: { [s: number]: string }) {
  for (const enumMember in e) {
    if (parseInt(enumMember, 10) >= 0) {
      console.log(e[enumMember]) // Value, such as 1,2,3
      console.log(parseInt(enumMember, 10)) // Text, such as Red,Green,Blue
    }
  }
}
this.getTextAndValues(Colors1)

如果你的枚举如下:

export enum Colors2 {
  Red = "Red",
  Green = "Green",
  Blue = "Blue"
}

要获得特定的文本和值:

console.log(Colors2.Red); // Red
console.log(Colors2["Red"]); // Red

获取值和文本列表:

public getTextAndValues(e: { [s: string]: string }) {
  for (const enumMember in e) {
    console.log(e[enumMember]);// Value, such as Red,Green,Blue
    console.log(enumMember); //  Text, such as Red,Green,Blue
  }
}
this.getTextAndValues(Colors2)

这不是你问题的确切答案,但它是解决你问题的一个技巧。

export module Gender {

  export enum Type {
    Female = 1,
    Male = 2
  };

  export const List = Object.freeze([
    Type[Type.Female] ,
    Type[Type.Male]
  ]);

}

您可以以自己想要的方式扩展列表模型。

export const List = Object.freeze([
    { name: Type[Type.Female], value: Type.Female } ,
    { name: Type[Type.Male], value: Type.Male }
  ]);

现在,你可以这样使用它:

for(const gender of Gender.List){
  console.log(gender.name);
  console.log(gender.value);
}

or:

if(i === Gender.Type.Male){
  console.log("I am a man.");
}

如果你想在html中获取名字

对于这个枚举

enum CanadianProvinces {
    AB,
    BC,
    MB,
    NB,
    NL,
    NT,
    NS,
    NU,
    ON,
    PE,
    QC,
    SK,
    YT
}

将组件中的变量赋值为

canadianProvinces = CanadianProvinces 

然后,在你的html

{{canadianProvinces[0]}}