打字稿类嵌套json猫

Question

您好，我有嵌套的 json 尝试转换类，但我弄错了。

类： export class Location { address: String city: String country: String position:{ lat:String, lng:String, } markers:{ lat:String, lng: String, label:String, draggable: boolean, iconUrl: String } }

我在 angular5 中转换类的 json 代码

placeMarker(pos) {
this.service.getGeocode(pos.coords.lat + "," + pos.coords.lng).subscribe(res => {
  var resp: any = res;
  console.log(resp)
  if (resp.results && resp.results.length > 0) {

    this.location.address = resp.results[0].formatted_address;
    this.location.position.lat = resp.results[0].geometry.location.lat;
    this.location.position.lng = resp.results[0].geometry.location.lng;

    resp.results[0].address_components.forEach(res=> {
      res.types.forEach(t=> {
        if (t == "administrative_area_level_1") {
          this.location.city = res.long_name;
        }
      });
    });
  }
})

}

单击angular5中的标记时出现以下错误，我可以设置地址但无法设置this.location.position.lat。

core.js:1350 ERROR TypeError: Cannot set property 'lat' of undefined
at SafeSubscriber.eval [as _next] (carpetfields.component.ts:55)
at SafeSubscriber.__tryOrUnsub (Subscriber.js:239)
at SafeSubscriber.next (Subscriber.js:186)
at Subscriber._next (Subscriber.js:127)
at Subscriber.next (Subscriber.js:91)
at MapSubscriber._next (map.js:85)
at MapSubscriber.Subscriber.next (Subscriber.js:91)
at XMLHttpRequest.onLoad (http.js:1556)
at ZoneDelegate.invokeTask (zone.js:425)
at Object.onInvokeTask (core.js:4620)

Answer 1

您正在设置 this.location.address，但没有设置 this.location.position。

您的代码应如下所示：

this.location.address = resp.results[0].formatted_address;
this.location.position = {
   lat: resp.results[0].geometry.location.lat,
   lng: resp.results[0].geometry.location.lng
}