Question

谷歌地图行为异常（随机工作或抛出错误）（TypeError：无法读取未定义的属性‘maps’）

2017-09-22

347

javascript reactjs google-maps

我似乎成功地将谷歌地图实现到我的反应应用程序中（获取用户位置并允许移动标记），但我收到随机错误“TypeError：无法读取未定义的属性‘maps’”。有时一切都运行正常，其他时候当我刷新时我会收到此错误。我不确定我应该提供哪段代码，所以也许我会发布我的完整地图组件和index.js文件

map：

import React from 'react';



class GoogleMap extends React.Component {

  constructor(props) {
    super(props);
    //const getCoords = this.props.getCoords;
    this.handleLocationError = this.handleLocationError.bind(this);
    this.state = {
      lat: '',
      lon: ''
    }
  }

  getCoords() {
    const lat = this.state.lat;
    const lon = this.state.lon;
    this.props.getCoords(lat, lon)

  }

  componentDidMount() {
    var map, infoWindow;

    map = new window.google.maps.Map(document.getElementById('map'), {
      center: { lat: -34.397, lng: 150.644 },
      zoom: 15
    });


    // Try HTML5 geolocation.
    if (navigator.geolocation) {
      navigator.geolocation.getCurrentPosition((position) => {
        var pos = {
          lat: position.coords.latitude,
          lng: position.coords.longitude
        };

        var marker = new window.google.maps.Marker({
          position: {
            lat: position.coords.latitude,
            lng: position.coords.longitude
          },
          map: map,
          draggable: true,
          title: 'Hello World!'
        })

        this.setState({
          lat: position.coords.latitude,
          lon: position.coords.longitude
        })

        this.getCoords();

        document.getElementById('test').innerHTML = '<p>Want to export: Current Lat: ' + position.coords.latitude + ' Current Lng: ' + position.coords.longitude + '</p>';
        map.setCenter(pos);

        //marker listeners
        window.google.maps.event.addListener(marker, 'dragstart', function () {
          console.log('marker dotkniety');
          document.getElementById('test').innerHTML = '<p>Currently dragging marker...</p>';
        });

        window.google.maps.event.addListener(marker, 'dragend', (e) => {
          console.log('marker upuszczony');
          document.getElementById('test').innerHTML = '<p>Want to export: Current Lat: ' + e.latLng.lat().toFixed(3) + ' Current Lng: ' + e.latLng.lng().toFixed(3) + '</p>';
          console.log(this, 'this inside the event listener');

          this.setState(({
            lat: e.latLng.lat(),
            lon: e.latLng.lng()
          }))

          this.getCoords();
        });


      }, () => {
        this.handleLocationError(true, map.getCenter());
      });

    } else {
      // Browser doesn't support Geolocation
      this.handleLocationError(false, map.getCenter());
    }
    console.log('DID MOUNT');
    console.log(this);
    console.log(this.state);
  }

  handleLocationError(browserHasGeolocation, pos, map) {}

  render() {

    return (

      <div>
        <div id='map' />
        <div id='test' />
      </div>
    )
  }
}
export default GoogleMap

和index.html

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta name="theme-color" content="#000000">
    <!--
      manifest.json provides metadata used when your web app is added to the
      homescreen on Android. See https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/
    -->
    <link rel="manifest" href="%PUBLIC_URL%/manifest.json">
    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
    <!--
      Notice the use of %PUBLIC_URL% in the tags above.
      It will be replaced with the URL of the `public` folder during the build.
      Only files inside the `public` folder can be referenced from the HTML.

      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
      work correctly both with client-side routing and a non-root public URL.
      Learn how to configure a non-root public URL by running `npm run build`.
    -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/latest/css/bootstrap.min.css">

    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBHek4tQK4jSQhVSoxw4s4c8tz_1z3xuNI&callback=initMap">
    </script>

    <title>App</title>
  </head>
  <body>
    <noscript>
      You need to enable JavaScript to run this app.
    </noscript>
    <div id="root"></div>

  </body>
</html>

我将不胜感激解决方案/提示或它如此行事的原因。

Answer 1

将谷歌地图安装为 npm 包

$ npm install google-maps

然后将其导入到您的组件 GoogleMapComponent.jsx:

import React from 'react';
import GoogleMapsLoader from 'google-maps';

GoogleMapsLoader.KEY = 'qwertyuiopasdfghjklzxcvbnm';

class GoogleMap extends React.Component {

  constructor(props) {
    super(props);
    //const getCoords = this.props.getCoords;
    this.handleLocationError = this.handleLocationError.bind(this);
    this.state = {
      lat: '',
      lon: ''
    }
  }
  componentDidMount() {
    GoogleMapsLoader.load((google) => {
      var map = new google.maps.Map(document.getElementById('map'), {
       center: { lat: -34.397, lng: 150.644 },
       zoom: 15
      });
      // rest of the code with maps
    });
    // rest of the code with react
  }