我试着使用下面的模式:
enum Option {
ONE = 'one',
TWO = 'two',
THREE = 'three'
}
interface OptionRequirement {
someBool: boolean;
someString: string;
}
interface OptionRequirements {
[key: Option]: OptionRequirement;
}
这对我来说似乎很简单，但是我得到了以下错误:
索引签名参数类型不能为联合类型。可以考虑使用映射对象类型。
我做错了什么?
当前回答
在我的例子中:
export type PossibleKeysType =
| 'userAgreement'
| 'privacy'
| 'people';
interface ProviderProps {
children: React.ReactNode;
items: {
// ↙ this colon was issue
[key: PossibleKeysType]: Array<SectionItemsType>;
};
}
我通过使用in操作符而不是使用:
~~~
interface ProviderProps {
children: React.ReactNode;
items: {
// ↙ use "in" operator
[key in PossibleKeysType]: Array<SectionItemsType>;
};
}
其他回答
在我的例子中:
export type PossibleKeysType =
| 'userAgreement'
| 'privacy'
| 'people';
interface ProviderProps {
children: React.ReactNode;
items: {
// ↙ this colon was issue
[key: PossibleKeysType]: Array<SectionItemsType>;
};
}
我通过使用in操作符而不是使用:
~~~
interface ProviderProps {
children: React.ReactNode;
items: {
// ↙ use "in" operator
[key in PossibleKeysType]: Array<SectionItemsType>;
};
}
与其使用接口，不如使用映射对象类型
enum Option {
ONE = 'one',
TWO = 'two',
THREE = 'three'
}
type OptionKeys = keyof typeof Option;
interface OptionRequirement {
someBool: boolean;
someString: string;
}
type OptionRequirements = { // note type, not interface
[key in OptionKeys]: OptionRequirement; // key in
}
我也遇到过类似的问题。我试图在创建angular表单验证器时只使用特定的键。
export enum FormErrorEnum {
unknown = 'unknown',
customError = 'customError',
}
export type FormError = keyof typeof FormErrorEnum;
以及用法:
static customFunction(param: number, param2: string): ValidatorFn {
return (control: AbstractControl): { [key: FormErrorEnum]?: any } => {
return { customError: {param, param2} };
};
}
这将允许使用1 - X个键。
我有一些类似的问题，但我的情况是在接口的另一个字段属性，所以我的解决方案作为一个可选字段属性的例子，有一个enum键:
export enum ACTION_INSTANCE_KEY {
cat = 'cat',
dog = 'dog',
cow = 'cow',
book = 'book'
}
type ActionInstances = {
[key in ACTION_INSTANCE_KEY]?: number; // cat id/dog id/cow id/ etc // <== optional
};
export interface EventAnalyticsAction extends ActionInstances { // <== need to be extended
marker: EVENT_ANALYTIC_ACTION_TYPE; // <== if you wanna add another field to interface
}
你可以使用TS“in”操作符，这样做:
enum Options {
ONE = 'one',
TWO = 'two',
THREE = 'three',
}
interface OptionRequirement {
someBool: boolean;
someString: string;
}
type OptionRequirements = {
[key in Options]: OptionRequirement; // Note that "key in".
}
