属性 'locations' 在类型 'Object' 上不存在

Question

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';


@Injectable()
export class LocationsProvider {

  data: any;

  constructor(public http: HttpClient) {

  }

  load() {

    if (this.data) {
     return Promise.resolve(this.data);
    }

    return new Promise(resolve => {

      this.http.get('assets/data/locations.json').subscribe(data => {

        this.data = this.applyHaversine(data.locations);

        this.data.sort((locationA, locationB) => {
          return locationA.distance - locationB.distance;
        });

        resolve(this.data);
      });

    });

  }

enter image description here

我在这里很新，对 ionic 也很陌生，我可能需要详细的解决方案，我似乎无法让 ionic 读取 json 文件

Answer 1

您在 data.locations 中遇到编译时错误，特别是 locations 未在数据属性上定义。

修复

告诉 TypeScript 它是例如使用断言：

  this.data = this.applyHaversine((data as any).locations);

Answer 2

如果您知道响应的类型，可以将泛型添加到 http.get<T>() 以键入 data。

interface SomeInterface {
    locations: Location[]
}

this.http.get('assets/data/locations.json')<SomeInterface>.subscribe(data => {
    this.data = this.applyHaversine(data.locations);
    ...
});

或者如果您不想为其创建接口（不推荐）

this.http.get('assets/data/locations.json')<SomeInterface>.subscribe((data: any) => {
    this.data = this.applyHaversine(data.locations);
    ...
});

属性 'locations' 在类型 'Object' 上不存在

Property 'locations' does not exist on type 'Object'

windows

json

geolocation

typescript

ionic-framework

修复