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
class EnumHelpers {
static getNamesAndValues<T extends number>(e: any) {
return EnumHelpers.getNames(e).map(n => ({ name: n, value: e[n] as T }));
}
static getNames(e: any) {
return EnumHelpers.getObjValues(e).filter(v => typeof v === 'string') as string[];
}
static getValues<T extends number>(e: any) {
return EnumHelpers.getObjValues(e).filter(v => typeof v === 'number') as T[];
}
static getSelectList<T extends number, U>(e: any, stringConverter: (arg: U) => string) {
const selectList = new Map<T, string>();
this.getValues(e).forEach(val => selectList.set(val as T, stringConverter(val as unknown as U)));
return selectList;
}
static getSelectListAsArray<T extends number, U>(e: any, stringConverter: (arg: U) => string) {
return Array.from(this.getSelectList(e, stringConverter), value => ({ value: value[0] as T, presentation: value[1] }));
}
private static getObjValues(e: any): (number | string)[] {
return Object.keys(e).map(k => e[k]);
}
}
其他回答
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]); ｝
另一种方法是
export const GoalNames = {
[GoalProgressMeasurements.Percentage] = 'Percentage',
[GoalProgressMeasurements.Numeric_Target] = 'Numeric Target',
[GoalProgressMeasurements.Completed_Tasks] = 'Completed Tasks',
[GoalProgressMeasurements.Average_Milestone_Progress] = 'Average Milestone Progress',
[GoalProgressMeasurements.Not_Measured] = 'Not Measured'
}
你可以调用:
const name = GoalNames[goalEnumVal];
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
}
我不建议在需要枚举条目列表的情况下使用TS enum。
在运行时，Enum是作为对象实现的，但它只在这种情况下工作:
enum X {
Z = 'z',
F = 'f'
};
console.log(Object.values(X))
console.log(Object.keys(X))
>>>
[LOG]: ["z", "f"]
[LOG]: ["Z", "F"]
在这种情况下，它与陷阱一起工作(TS让你通过它的数值访问值):
enum X {
Z,
F
};
console.log(Object.values(X))
console.log(Object.keys(X))
>>>
[LOG]: ["Z", "F", 0, 1]
[LOG]: ["0", "1", "Z", "F"]
因此，根据Enum定义，任何你写在Enum上循环的函数都将工作/失败。这是…不好的。
我的结论是:Enum不是被设计用来作为对象的。如果你需要访问键和值集合，请使用const而不是enum:
const Enumed = {
X: 1,
Y: 2
}
Typescript将控制对象键的存在，你将能够使用object。钥匙等，以安全一致的方式。
this worked for me :
export enum FeedBackType {
FEEDBACK1= 'FEEDBACK1',
FEEDBACK2= 'FEEDBACK2',
FEEDBACK3= 'FEEDBACK3',
}
-----------------------------------------------------------------
export function getTypeFeedBackList() {
let feedbackList: FeedBackType[] = [];
Object.keys(FeedBackType).map((key) => {
let strEnum = key as unknown as FeedBackType;
feedbackList.push(strEnum);
});
return feedbackList;
}
----------------------------------------------------------------
declare this :
public feedbackList: FeedBackType[] = [];
and after call your function in :
ngOnInit(): void {
this.feedbackList = getTypeFeedBackList();
console.log(this.feedbackList);
}
Happy coding ;)
