以下代码可用于在TypeScript中创建enum:
enum e {
hello = 1,
world = 2
};
这些值可以通过以下方式访问:
e.hello;
e.world;
我如何创建一个字符串值enum ?
enum e {
hello = "hello", // error: cannot convert string to e
world = "world" // error
};
以下代码可用于在TypeScript中创建enum:
enum e {
hello = 1,
world = 2
};
这些值可以通过以下方式访问:
e.hello;
e.world;
我如何创建一个字符串值enum ?
enum e {
hello = "hello", // error: cannot convert string to e
world = "world" // error
};
当前回答
一个俗套的说法是:-
CallStatus.ts
enum Status
{
PENDING_SCHEDULING,
SCHEDULED,
CANCELLED,
COMPLETED,
IN_PROGRESS,
FAILED,
POSTPONED
}
export = Status
Utils.ts
static getEnumString(enum:any, key:any):string
{
return enum[enum[key]];
}
如何使用
Utils.getEnumString(Status, Status.COMPLETED); // = "COMPLETED"
其他回答
打印稿0.9.0.1
enum e{
hello = 1,
somestr = 'world'
};
alert(e[1] + ' ' + e.somestr);
打印稿操场
这对我来说很管用:
class MyClass {
static MyEnum: { Value1; Value2; Value3; }
= {
Value1: "Value1",
Value2: "Value2",
Value3: "Value3"
};
}
or
module MyModule {
export var MyEnum: { Value1; Value2; Value3; }
= {
Value1: "Value1",
Value2: "Value2",
Value3: "Value3"
};
}
8)
更新:在发布这篇文章后不久,我发现了另一种方法,但忘记发布更新(然而,上面已经有人提到过了):
enum MyEnum {
value1 = <any>"value1 ",
value2 = <any>"value2 ",
value3 = <any>"value3 "
}
TypeScript < 2.4
/** Utility function to create a K:V from a list of strings */
function strEnum<T extends string>(o: Array<T>): {[K in T]: K} {
return o.reduce((res, key) => {
res[key] = key;
return res;
}, Object.create(null));
}
/**
* Sample create a string enum
*/
/** Create a K:V */
const Direction = strEnum([
'North',
'South',
'East',
'West'
])
/** Create a Type */
type Direction = keyof typeof Direction;
/**
* Sample using a string enum
*/
let sample: Direction;
sample = Direction.North; // Okay
sample = 'North'; // Okay
sample = 'AnythingElse'; // ERROR!
从https://basarat.gitbooks.io/typescript/docs/types/literal-types.html
到源代码链接,你可以找到更多更简单的方法来实现字符串文字类型
我在TypeScript 1.5中尝试过,如下所示,它对我来说很有效
module App.Constants {
export enum e{
Hello= ("Hello") as any,
World= ("World") as any
}
}
这里有一个相当干净的解决方案,它允许继承,使用TypeScript 2.0。我没有在早期的版本上尝试过。
附加条件:该值可以是任何类型!
export class Enum<T> {
public constructor(public readonly value: T) {}
public toString() {
return this.value.toString();
}
}
export class PrimaryColor extends Enum<string> {
public static readonly Red = new Enum('#FF0000');
public static readonly Green = new Enum('#00FF00');
public static readonly Blue = new Enum('#0000FF');
}
export class Color extends PrimaryColor {
public static readonly White = new Enum('#FFFFFF');
public static readonly Black = new Enum('#000000');
}
// Usage:
console.log(PrimaryColor.Red);
// Output: Enum { value: '#FF0000' }
console.log(Color.Red); // inherited!
// Output: Enum { value: '#FF0000' }
console.log(Color.Red.value); // we have to call .value to get the value.
// Output: #FF0000
console.log(Color.Red.toString()); // toString() works too.
// Output: #FF0000
class Thing {
color: Color;
}
let thing: Thing = {
color: Color.Red,
};
switch (thing.color) {
case Color.Red: // ...
case Color.White: // ...
}