您可以通过启用点击事件处理、为屏幕阅读器添加描述性文本并调整标记比例,让标记更易于访问。
- 可点击(或可拖动)的标记可以响应键盘和鼠标输入。
title
选项中指定的文本可由屏幕阅读器读取,当用户将鼠标指针悬停在标记上时,系统会显示该文本。- 增大标记的尺寸后,在所有设备(尤其是触摸屏设备)上与之交互时就不需要那么大的精度,同时无障碍体验也更好。默认的标记尺寸符合 WCAG AA 最小尺寸标准,但如果开发者希望遵循 WCAG AAA 目标尺寸标准,则应增加标记尺寸。
如需了解如何更改标记缩放比例、添加标题文本等,请参阅自定义基本标记。
以下示例展示了一张地图,其中包含五个可点击且可聚焦的标记,这些标记包含标题文本,并且已设为 1.5 倍缩放比例:
要使用键盘在标记间导航,请按以下说明操作:
- 使用 Tab 键将焦点移至第一个标记;如果同一地图上有多个标记,可使用箭头键在标记之间循环切换。
- 如果标记可点击,按 Enter 键即可“点击”它。如果某个标记有信息窗口,您可以点击该标记或者按 Enter 键或空格键打开其信息窗口。关闭信息窗口后,焦点将返回到关联的标记。
- 再按一次 Tab 键,即可继续在其余地图控件之间移动。
将标记设置为可点击
本部分介绍了如何使标记响应点击事件。 如需将标记设置为可点击,请执行以下操作:
- 将
gmpClickable
属性设置为true
。
TypeScript
const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, });
JavaScript
const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, });
- 添加点击事件监听器以响应用户输入。
TypeScript
// Add a click listener for each marker, and set up the info window. marker.addListener('click', ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); });
JavaScript
// Add a click listener for each marker, and set up the info window. marker.addListener("click", ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); });
如要使标记不再可点击,请调用
removeListener
以移除点击事件监听器:// Remove the listener. google.maps.event.removeListener(clickListener);
如需进一步增强无障碍功能,请执行以下操作:
- 使用
AdvancedMarkerElement.title
选项为标记设置描述性文本。 - 使用
PinElement
的scale
属性增大标记比例。
完整示例代码
查看完整的示例源代码
TypeScript
async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary; const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary("marker") as google.maps.MarkerLibrary; const map = new Map(document.getElementById("map") as HTMLElement, { zoom: 12, center: { lat: 34.84555, lng: -111.8035 }, mapId: '4504f8b37365c3d0', }); // Set LatLng and title text for the markers. The first marker (Boynton Pass) // receives the initial focus when tab is pressed. Use arrow keys to move // between markers; press tab again to cycle through the map controls. const tourStops = [ { position: { lat: 34.8791806, lng: -111.8265049 }, title: "Boynton Pass" }, { position: { lat: 34.8559195, lng: -111.7988186 }, title: "Airport Mesa" }, { position: { lat: 34.832149, lng: -111.7695277 }, title: "Chapel of the Holy Cross" }, { position: { lat: 34.823736, lng: -111.8001857 }, title: "Red Rock Crossing" }, { position: { lat: 34.800326, lng: -111.7665047 }, title: "Bell Rock" }, ]; // Create an info window to share between markers. const infoWindow = new InfoWindow(); // Create the markers. tourStops.forEach(({position, title}, i) => { const pin = new PinElement({ glyph: `${i + 1}`, scale: 1.5, }); const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, }); // Add a click listener for each marker, and set up the info window. marker.addListener('click', ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); }); }); } initMap();
JavaScript
async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps"); const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary( "marker", ); const map = new Map(document.getElementById("map"), { zoom: 12, center: { lat: 34.84555, lng: -111.8035 }, mapId: "4504f8b37365c3d0", }); // Set LatLng and title text for the markers. The first marker (Boynton Pass) // receives the initial focus when tab is pressed. Use arrow keys to move // between markers; press tab again to cycle through the map controls. const tourStops = [ { position: { lat: 34.8791806, lng: -111.8265049 }, title: "Boynton Pass", }, { position: { lat: 34.8559195, lng: -111.7988186 }, title: "Airport Mesa", }, { position: { lat: 34.832149, lng: -111.7695277 }, title: "Chapel of the Holy Cross", }, { position: { lat: 34.823736, lng: -111.8001857 }, title: "Red Rock Crossing", }, { position: { lat: 34.800326, lng: -111.7665047 }, title: "Bell Rock", }, ]; // Create an info window to share between markers. const infoWindow = new InfoWindow(); // Create the markers. tourStops.forEach(({ position, title }, i) => { const pin = new PinElement({ glyph: `${i + 1}`, scale: 1.5, }); const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, }); // Add a click listener for each marker, and set up the info window. marker.addListener("click", ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); }); }); } initMap();
CSS
/* * Always set the map height explicitly to define the size of the div element * that contains the map. */ #map { height: 100%; } /* * Optional: Makes the sample page fill the window. */ html, body { height: 100%; margin: 0; padding: 0; }
HTML
<html> <head> <title>Advanced Marker Accessibility</title> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <!-- prettier-ignore --> <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${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: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "beta"});</script> </body> </html>