Question

GetLocation(address: string) {
  var geocoder = new google.maps.Geocoder();
  geocoder.geocode({ 'address': address }, (results, status) => {
    if (status == google.maps.GeocoderStatus.OK) {
      this.lat = results[0].geometry.location.lat(); 
      this.lng = results[0].geometry.location.lng();   <== this.lat value is undefined
    }
    else {
      alert("Something went wrong : " + status);
    }
  });
}

在这里，我无法在地址解析功能内分配组件级别变量“ lat”和“ lng”的值。仅供参考：结果对象的位置对象中有值，但分配值后仍不确定，我不知道为什么？

Answer 1

import { Component, OnInit, NgZone } from '@angular/core';  <= 1. I have to import NgZone

constructor(private ngZone: NgZone) { }  <= 2. declared it here

ngOnInit() { }

GetLocation(address: string) {
  var geocoder = new google.maps.Geocoder();
  geocoder.geocode({ 'address': address }, (results, status) => this.ngZone.run(() => { <= 3. and used it here
    if (status == google.maps.GeocoderStatus.OK) {
      this.lat = results[0].geometry.location.lat();
      this.lng = results[0].geometry.location.lng();
    }
    else {
      alert("Something went wrong : " + status);
    }
  }));
}

我找到了解决方案。我必须从'@ angular / core'导入NgZone 并在回调函数中使用了this.ngZone.run（）函数（如第3条提示所示）。

无法在地址解析功能内分配组件变量值

1 个答案: