javascript - Google Maps DrawingManager 在 Angular 中未定义

Question

我试图通过使用 Angular 单击按钮来更改 Google map 绘图管理器的几个选项。但是我收到错误消息，指出 DrawingManager 变量未定义。

我在 Angular 组件的 ngAfterViewInit 函数中初始化了 Google Maps 和 DrawingManager。 Google Map 对象和 Drawing Manager 对象被分配给组件中的变量，如代码所示。我想通过单击组件中的按钮来更改绘图管理器的几个选项。单击按钮调用“drawControlEnable”函数。但是 DrawingManager 对象在“drawControlEnable”函数中是未定义的。我已将 Google map 脚本和组件代码放入 index.html 中。

Index.html

<script async defer src="https://maps.googleapis.com/maps/api/js?key=XXXXX&libraries=drawing,geometry"></script>

Angular 分量

import {Component, OnInit, ViewChild, AfterViewInit} from '@angular/core';
import { } from '@types/googlemaps';

.....
.....

@ViewChild('gmap') gmapElement: any;
map: google.maps.Map;
shapes = [];
coordinatesArray = [];
drawingManager: any;

ngAfterViewInit() {
    var mapProp = {
      center: new google.maps.LatLng(7.515073, 80.723066),
      zoom: 8,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    this.map = new google.maps.Map(this.gmapElement.nativeElement, mapProp);

    this.drawingManager = new google.maps.drawing.DrawingManager({
        drawingMode: null,
        drawingControl: false,
        drawingControlOptions: {
           position: google.maps.ControlPosition.TOP_CENTER,
           drawingModes: ['polygon']
        },
        markerOptions: {icon: 'https://developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png'},
        polygonOptions: {
           editable: true,
           draggable: true
        }
    });
    this.drawingManager.setMap(this.map);
}
.....
.....
drawControlEnable() {
this.drawingManager.setDrawingMode(google.maps.drawing.OverlayType.MARKER);
    this.drawingManager.setOptions({drawingControl : true});
}

如何通过单击按钮更改 DrawingManager 选项？

Answer 1

这就是我创建 map 并使用按钮更改绘图控制选项的方式:首先我声明了两个变量:一个用于 map ，一个用于绘图管理器

  theMap: any;
  drawingManager: any;

我在 ngOnInit 中创建 map 并调用绘图管理器:

this.theMap = this.initMap(lat, lng);

if(this.theMap) {
      this.initDrawingManager(this.theMap)
}

创建 map 和初始化绘图管理器的两个函数是:

  initMap(lat, lng) {
    let mapProp = {
      center: new google.maps.LatLng(lat, lng),
      zoom: 16,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };

    let map = new google.maps.Map(document.getElementById("map"), mapProp);

    let marker = new google.maps.Marker({
      icon: 'https://developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png',
      animation: google.maps.Animation.DROP,
      position: { lat: lat, lng: lng },
      map: map
    })

    return map;
  }

和

  initDrawingManager(map) {
    this.drawingManager = new google.maps.drawing.DrawingManager({
      // drawingMode: google.maps.drawing.OverlayType.MARKER,
      drawingControl: false,
      drawingControlOptions: {
        position: google.maps.ControlPosition.TOP_CENTER,
        drawingModes: ['circle', 'polygon']
      },
      // markerOptions: {icon: 'https://developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png'},
      polygonOptions: {
        draggable: true,
        editable: true
      },
      circleOptions: {
        // fillColor: '#ffff00',
        // fillOpacity: 1,
        // strokeWeight: 5,
        draggable: true,
        clickable: true,
        editable: true,
        zIndex: 1
      }
    });

    this.drawingManager.setMap(map);
  }

改变drawingControl选项的函数是:

  change() {
    this.drawingManager.setOptions({
      drawingControl: true
    });
  }

HTML 是:

<button
   (click)="change()">
   change
</button>

通过单击按钮，绘图控件将出现在 map 上。

我们的区别在于我在 ngOnInit 中创建 map 。