如需加载 Maps JavaScript API 的 JavaScript 代码,您 需要在网页上添加 引导程序加载器脚本,格式如下:
<script> (g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})({ key: "YOUR_API_KEY", v: "weekly", // Use the 'v' parameter to indicate the version to use (weekly, beta, alpha, etc.). // Add other bootstrap parameters as needed, using camel case. }); </script>
Maps JavaScript API 由多个 库组成,这些库
不会在您明确请求之前加载。将组件
分散到各个库中,可使该 API 快速加载和解析,这样,只有在需要加载和解析库时,才会产生额外的开销。使用
动态库导入时,内嵌引导加载程序默认不会加载任何库
(甚至不会加载
core
或
maps);
在调用
google.maps.importLibrary()之前,
Maps JavaScript API 的任何部分都不会加载。
若要在运行时加载库,请使用 await 运算符从 async 函数中调用
google.maps.importLibrary()
。假设仅加载所请求的
库,并为代码使用的每个库调用
google.maps.importLibrary()
。例如:
const { Map } = await google.maps.importLibrary("maps");
以下代码示例展示了如何同时加载
maps
和
marker
库以访问
Map
和
AdvancedMarkerElement
类:
TypeScript
async function init(): Promise<void> { // Request the needed libraries. const [{ AdvancedMarkerElement }] = await Promise.all([ google.maps.importLibrary('marker'), google.maps.importLibrary('maps'), ]); // Get the gmp-map element. const mapElement = document.querySelector('gmp-map')!; // Get the inner map. const innerMap = mapElement.innerMap; // Set map options. innerMap.setOptions({ mapTypeControl: false, }); // Add a marker positioned at the map center (Uluru). new AdvancedMarkerElement({ map: innerMap, position: mapElement.center, title: 'Uluru/Ayers Rock', }); } void init();
JavaScript
async function init() { // Request the needed libraries. const [{ AdvancedMarkerElement }] = await Promise.all([ google.maps.importLibrary('marker'), google.maps.importLibrary('maps'), ]); // Get the gmp-map element. const mapElement = document.querySelector('gmp-map'); // Get the inner map. const innerMap = mapElement.innerMap; // Set map options. innerMap.setOptions({ mapTypeControl: false, }); // Add a marker positioned at the map center (Uluru). new AdvancedMarkerElement({ map: innerMap, position: mapElement.center, title: 'Uluru/Ayers Rock', }); } void init();
可用的库
core(google.maps.CoreLibrary)maps(google.maps.MapsLibrary)maps3d(google.maps.Maps3DLibrary)places(google.maps.PlacesLibrary)geocoding(google.maps.GeocodingLibrary)routes(google.maps.RoutesLibrary)marker(google.maps.MarkerLibrary)geometry(google.maps.GeometryLibrary)elevation(google.maps.ElevationLibrary)streetView(google.maps.StreetViewLibrary)journeySharing(google.maps.JourneySharingLibrary)visualization(google.maps.VisualizationLibrary)airQuality(google.maps.AirQualityLibrary)addressValidation(google.maps.AddressValidationLibrary)drawing(google.maps.DrawingLibrary)(已弃用)
以下引导程序请求展示了如何将对 Maps JavaScript API 的
google.maps.geometry 库的请求添加到直接
脚本加载标记中:
<script async
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&loading=async&libraries=geometry&callback=initMap">
</script>若要请求多个库,请用英文逗号分隔:
<script async
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&loading=async&libraries=geometry,places&callback=initMap">
</script>