谷歌Maps Api相当新。我有一个数据数组,我想循环遍历并在地图上绘制。看似相当简单,但我发现的所有多标记教程都相当复杂。

让我们以谷歌网站的数据数组为例:

var locations = [
  ['Bondi Beach', -33.890542, 151.274856, 4],
  ['Coogee Beach', -33.923036, 151.259052, 5],
  ['Cronulla Beach', -34.028249, 151.157507, 3],
  ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
  ['Maroubra Beach', -33.950198, 151.259302, 1]
];

我只是想绘制所有这些点,并在单击时弹出一个infoWindow来显示名称。


当前回答

我想我将把这个放在这里,因为它似乎是那些开始使用谷歌地图API的一个流行的着陆点。在客户端呈现多个标记可能是许多映射应用程序性能下降的原因。很难进行基准测试、修复,在某些情况下甚至很难确定存在问题(由于浏览器实现的差异、客户端可用的硬件、移动设备等等)。

开始解决这个问题的最简单方法是使用标记集群解决方案。其基本思想是将地理上相似的位置分组,并显示点的数量。当用户放大地图时,这些组会展开,显示出下面的单个标记。

也许最简单的实现是markerclusterer库。基本实现如下(在库导入之后):

<script type="text/javascript">
  function initialize() {
    var center = new google.maps.LatLng(37.4419, -122.1419);

    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 3,
      center: center,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });

    var markers = [];
    for (var i = 0; i < 100; i++) {
      var location = yourData.location[i];
      var latLng = new google.maps.LatLng(location.latitude,
          location.longitude);
      var marker = new google.maps.Marker({
        position: latLng
      });
      markers.push(marker);
    }
    var markerCluster = new MarkerClusterer({map, markers});
  }
  google.maps.event.addDomListener(window, 'load', initialize);
</script>

标记不是直接添加到映射中,而是添加到数组中。然后将该数组传递给为您处理复杂计算的库,并将其附加到映射。

这些实现不仅极大地提高了客户端性能,而且在许多情况下,它们还会导致更简单、更整洁的UI,更容易在更大范围内消化数据。

谷歌提供了其他实现。

希望这能帮助到那些刚接触映射的人。

其他回答

下面是一个几乎完整的示例javascript函数,它允许在JSONObject中定义多个标记。

它将只显示在地图边界内的标记。

这很重要,这样你就不用做额外的工作了。

你也可以设置一个标记的限制,这样你就不会显示一个极端数量的标记(如果有可能在你的使用);

如果地图中心的变化不超过500米,就不会显示标记。 这很重要,因为如果用户单击标记并在此过程中意外地拖动了地图,您不希望地图重新加载标记。

我将这个函数附加到地图的空闲事件侦听器,因此标记只在地图空闲时显示,并在不同的事件后重新显示标记。

活动屏幕截图 在信息窗口中显示更多内容的屏幕截图有一个小变化。 粘贴自pastbin.com

<script src=“//pastebin.com/embed_js/uWAbRxfg”></script>

来自谷歌Map API示例:

function initialize() {
  var myOptions = {
    zoom: 10,
    center: new google.maps.LatLng(-33.9, 151.2),
    mapTypeId: google.maps.MapTypeId.ROADMAP
  }
  var map = new google.maps.Map(document.getElementById("map_canvas"),
                                myOptions);

  setMarkers(map, beaches);
}

/**
 * Data for the markers consisting of a name, a LatLng and a zIndex for
 * the order in which these markers should display on top of each
 * other.
 */
var beaches = [
  ['Bondi Beach', -33.890542, 151.274856, 4],
  ['Coogee Beach', -33.923036, 151.259052, 5],
  ['Cronulla Beach', -34.028249, 151.157507, 3],
  ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
  ['Maroubra Beach', -33.950198, 151.259302, 1]
];

function setMarkers(map, locations) {
  // Add markers to the map

  // Marker sizes are expressed as a Size of X,Y
  // where the origin of the image (0,0) is located
  // in the top left of the image.

  // Origins, anchor positions and coordinates of the marker
  // increase in the X direction to the right and in
  // the Y direction down.
  var image = new google.maps.MarkerImage('images/beachflag.png',
      // This marker is 20 pixels wide by 32 pixels tall.
      new google.maps.Size(20, 32),
      // The origin for this image is 0,0.
      new google.maps.Point(0,0),
      // The anchor for this image is the base of the flagpole at 0,32.
      new google.maps.Point(0, 32));
  var shadow = new google.maps.MarkerImage('images/beachflag_shadow.png',
      // The shadow image is larger in the horizontal dimension
      // while the position and offset are the same as for the main image.
      new google.maps.Size(37, 32),
      new google.maps.Point(0,0),
      new google.maps.Point(0, 32));
      // Shapes define the clickable region of the icon.
      // The type defines an HTML &lt;area&gt; element 'poly' which
      // traces out a polygon as a series of X,Y points. The final
      // coordinate closes the poly by connecting to the first
      // coordinate.
  var shape = {
      coord: [1, 1, 1, 20, 18, 20, 18 , 1],
      type: 'poly'
  };
  for (var i = 0; i < locations.length; i++) {
    var beach = locations[i];
    var myLatLng = new google.maps.LatLng(beach[1], beach[2]);
    var marker = new google.maps.Marker({
        position: myLatLng,
        map: map,
        shadow: shadow,
        icon: image,
        shape: shape,
        title: beach[0],
        zIndex: beach[3]
    });
  }
}

下面是一个Reactjs中多个标记的例子。

下面是映射组件

import React from 'react';
import PropTypes from 'prop-types';
import { Map, InfoWindow, Marker, GoogleApiWrapper } from 'google-maps-react';

const MapContainer = (props) => {
  const [mapConfigurations, setMapConfigurations] = useState({
    showingInfoWindow: false,
    activeMarker: {},
    selectedPlace: {}
  });

  var points = [
    { lat: 42.02, lng: -77.01 },
    { lat: 42.03, lng: -77.02 },
    { lat: 41.03, lng: -77.04 },
    { lat: 42.05, lng: -77.02 }
  ]
  const onMarkerClick = (newProps, marker) => {};

  if (!props.google) {
    return <div>Loading...</div>;
  }

  return (
    <div className="custom-map-container">
      <Map
        style={{
          minWidth: '200px',
          minHeight: '140px',
          width: '100%',
          height: '100%',
          position: 'relative'
        }}
        initialCenter={{
          lat: 42.39,
          lng: -72.52
        }}
        google={props.google}
        zoom={16}
      >
        {points.map(coordinates => (
          <Marker
            position={{ lat: coordinates.lat, lng: coordinates.lng }}
            onClick={onMarkerClick}
            icon={{
              url: 'https://res.cloudinary.com/mybukka/image/upload/c_scale,r_50,w_30,h_30/v1580550858/yaiwq492u1lwuy2lb9ua.png',
            anchor: new google.maps.Point(32, 32), // eslint-disable-line
            scaledSize: new google.maps.Size(30, 30)  // eslint-disable-line
            }}
            name={name}
          />))}
        <InfoWindow
          marker={mapConfigurations.activeMarker}
          visible={mapConfigurations.showingInfoWindow}
        >
          <div>
            <h1>{mapConfigurations.selectedPlace.name}</h1>
          </div>
        </InfoWindow>
      </Map>
    </div>
  );
};

export default GoogleApiWrapper({
  apiKey: process.env.GOOGLE_API_KEY,
  v: '3'
})(MapContainer);

MapContainer.propTypes = {
  google: PropTypes.shape({}).isRequired,
};

异步版本:

<script type="text/javascript">
  function initialize() {
    var locations = [
      ['Bondi Beach', -33.890542, 151.274856, 4],
      ['Coogee Beach', -33.923036, 151.259052, 5],
      ['Cronulla Beach', -34.028249, 151.157507, 3],
      ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
      ['Maroubra Beach', -33.950198, 151.259302, 1]
    ];

    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 10,
      center: new google.maps.LatLng(-33.92, 151.25),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });

    var infowindow = new google.maps.InfoWindow();

    var marker, i;

    for (i = 0; i < locations.length; i++) {  
      marker = new google.maps.Marker({
        position: new google.maps.LatLng(locations[i][1], locations[i][2]),
        map: map
      });

      google.maps.event.addListener(marker, 'click', (function(marker, i) {
        return function() {
          infowindow.setContent(locations[i][0]);
          infowindow.open(map, marker);
        }
      })(marker, i));
    }
}

function loadScript() {
  var script = document.createElement('script');
  script.type = 'text/javascript';
  script.src = 'https://maps.googleapis.com/maps/api/js?v=3.exp&' +
      'callback=initialize';
  document.body.appendChild(script);
}

window.onload = loadScript;
  </script>

var arr = new Array();
    function initialize() { 
        var i;  
        var Locations = [
                {
                  lat:48.856614, 
                  lon:2.3522219000000177, 
                  address:'Paris',
                  gval:'25.5',
                  aType:'Non-Commodity',
                  title:'Paris',
                  descr:'Paris'           
                },        
                    {
                  lat: 55.7512419, 
                  lon: 37.6184217,
                  address:'Moscow',
                  gval:'11.5',
                  aType:'Non-Commodity',
                  title:'Moscow',
                  descr:'Moscow Airport'              
                },     

                {
              lat:-9.481553000000002, 
              lon:147.190242, 
              address:'Port Moresby',
              gval:'1',
              aType:'Oil',
              title:'Papua New Guinea',
              descr:'Papua New Guinea 123123123'              
            },
            {
           lat:20.5200,
           lon:77.7500,
           address:'Indore',
            gval:'1',
            aType:'Oil',
            title:'Indore, India',
            descr:'Airport India'
        }
    ];

    var myOptions = {
        zoom: 2,
        center: new google.maps.LatLng(51.9000,8.4731),
        mapTypeId: google.maps.MapTypeId.ROADMAP
    };

    var map = new google.maps.Map(document.getElementById("map"), myOptions);

    var infowindow =  new google.maps.InfoWindow({
        content: ''
    });

    for (i = 0; i < Locations.length; i++) {
            size=15;        
            var img=new google.maps.MarkerImage('marker.png',           
                new google.maps.Size(size, size),
                new google.maps.Point(0,0),
                new google.maps.Point(size/2, size/2)
           );

        var marker = new google.maps.Marker({
            map: map,
            title: Locations[i].title,
            position: new google.maps.LatLng(Locations[i].lat, Locations[i].lon),           
                icon: img
        });

        bindInfoWindow(marker, map, infowindow, "<p>" + Locations[i].descr + "</p>",Locations[i].title);  

    }

}

function bindInfoWindow(marker, map, infowindow, html, Ltitle) { 
    google.maps.event.addListener(marker, 'mouseover', function() {
            infowindow.setContent(html); 
            infowindow.open(map, marker); 

    });
    google.maps.event.addListener(marker, 'mouseout', function() {
        infowindow.close();

    }); 
} 

完整的工作示例。你可以复制,粘贴和使用。