错误“不能对类型缺少调用或构造签名的表达式使用'new'."导入Esri类型时 [英] Error "Cannot use 'new' with an expression whose type lacks a call or construct signature." when importing Esri types

问题描述

我觉得这里确实缺少一些简单的东西.我正在构建一个使用Esri ArcGIS API的类，但是当我从arcgis-js-api的d.ts文件导入类型定义时，出现打字稿错误无法在表达式中使用'new'其类型缺少调用或构造签名."

I feel like there is something really simple that I am missing here. I've got a class that I am building out that uses Esri ArcGIS API, but when I import the type definitions from the arcgis-js-api's d.ts file, I get the typescript error "Cannot use 'new' with an expression whose type lacks a call or construct signature."

例如:

import * as IMap from 'esri/Map';

export class Foo {
    bar: (Map: IMap) {
        const map = new Map(); // <-- error here
    }
}

d.ts文件中的相关片段:

declare namespace __esri {
    /* snip */
    interface Map extends Accessor, LayersMixin {
        allLayers: Collection;
        basemap: Basemap;
        ground: Ground;
    }

    interface MapConstructor {
        new(properties?: MapProperties): Map;
    }

    export const Map: MapConstructor;
    /* snip */
}

declare module "esri/Map" {
    import Map = __esri.Map;
    export = Map;
}

看起来类型定义对我来说是正确的，所以我做错了什么，这会使Typescript认为IMap类型没有构造函数?

Looks like the type definition is correct to me, so what am I doing wrong that would make Typescript think that the IMap type doesn't have a constructor?

推荐答案

参数中的Map是IMap类型的实例.如果您想将其键入为构造函数，则将其键入为typeof IMap:

The Map in your parameter is an instance of the IMap type. If you wanted to type it as the constructor instead, type it as typeof IMap:

bar (Map: typeof IMap) {
    const map = new Map(); 
}

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