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
我是这样解的
const listKeys = Object.keys(TripStatus); //TripStatus is enum type
const numOfItem = listKeys.length/2;
for(let i=0; i<numOfItem; i++){
this.listStatus.push({
id: listKeys[i],
name: listKeys[numOfItem+i]
})
}
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
有一个简单的解决方案，当你运行object。Keys (Enum)它会给你一个值和键的数组，在第一个slice Values中，在第二个slice key中，为什么我们不直接返回第二个slice，下面的代码对我来说是有用的。
enum Enum {
ONE,
TWO,
THREE,
FOUR,
FIVE,
SIX,
SEVEN
}
const keys = Object.keys(Enum);
console.log(keys.slice(keys.length / 2));
export function enumKeys(E: any): string[] {
return Object.keys(E).filter(k => isNaN(Number(k)));
}
export function enumValues(E: any): string[] | number[] {
return enumKeys(E).map(k => E[k as any]);
}
两者都适用:
enum TestA {
RED = "red",
BLUE = "blue"
}
enum TestB {
ONE = 1,
TWO = 2
}
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]);
}
由于具有字符串值的枚举不同于具有数字值的枚举，因此最好从@user8363解决方案中过滤非数字。
这里是你如何从enum字符串中获取值，数字混合:
/ /帮助 export const StringIsNotNumber = value => isNaN(Number(value)) === true; //将枚举转换为数组 导出函数enumToArray(枚举){ 返回种(enumme) .filter (StringIsNotNumber) .map(key => enumme[key]); ｝
