總覽
請將地圖項目圖層設計成能夠回應 mousemove
和 click
事件,並使用這些地圖項目,傳回點選邊界的相關資訊。這項資訊
包括 ID、顯示名稱和地圖項目類型。下方地圖範例顯示
以及事件處理代碼
根據使用者互動設定多邊形樣式 (mousemove
會變更邊框
粗細,click
會遮蔽背景顏色並導致資訊視窗
螢幕)。
啟用地圖項目圖層事件
請按照下列步驟啟用地圖項目圖層上的事件:
找出您要註冊的每個事件,對地圖項目圖層呼叫
addListener()
函式,註冊事件通知的地圖項目圖層。在本例中,地圖也會取得事件監聽器。TypeScript
敬上// Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer('ADMINISTRATIVE_AREA_LEVEL_2'); // Add the event listeners for the feature layer. featureLayer.addListener('click', handleClick); featureLayer.addListener('mousemove', handleMouseMove); // Map event listener. map.addListener('mousemove', () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } });
JavaScript
// Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer("ADMINISTRATIVE_AREA_LEVEL_2"); // Add the event listeners for the feature layer. featureLayer.addListener("click", handleClick); featureLayer.addListener("mousemove", handleMouseMove); // Map event listener. map.addListener("mousemove", () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } });
您可以根據互動類型,加入事件處理常式程式碼來設定所選多邊形的樣式。
TypeScript
敬上function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map(f => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map(f => f.placeId); featureLayer.style = applyStyle; }
JavaScript
function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map((f) => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map((f) => f.placeId); featureLayer.style = applyStyle; }
您可以使用地圖項目樣式函式來套用樣式。這裡顯示的地圖項目樣式函式,會有條件地根據互動類型套用樣式。三段 樣式定義如下:一種會將
mousemove
的邊框設為粗體,1 到 變更背景,並在click
顯示資訊視窗和預設樣式。TypeScript
// Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: '#810FCB', strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: 'white', fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: '#810FCB', fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; }
JavaScript
// Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: "#810FCB", strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: "white", fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: "#810FCB", fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; }
完整程式碼範例
TypeScript
let map: google.maps.Map; let featureLayer; let infoWindow; let lastInteractedFeatureIds = []; let lastClickedFeatureIds = []; function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map(f => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map(f => f.placeId); featureLayer.style = applyStyle; } async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary('maps') as google.maps.MapsLibrary; map = new Map(document.getElementById('map') as HTMLElement, { center: {lat: 39.23, lng: -105.73}, zoom: 8, // In the cloud console, configure your Map ID with a style that enables the // 'Administrative Area Level 2' Data Driven Styling type. mapId: 'a3efe1c035bad51b', // Substitute your own map ID. mapTypeControl: false, }); // Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer('ADMINISTRATIVE_AREA_LEVEL_2'); // Add the event listeners for the feature layer. featureLayer.addListener('click', handleClick); featureLayer.addListener('mousemove', handleMouseMove); // Map event listener. map.addListener('mousemove', () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } }); // Create the infowindow. infoWindow = new InfoWindow({}); // Apply style on load, to enable clicking. featureLayer.style = applyStyle; } // Helper function for the infowindow. async function createInfoWindow(event) { let feature = event.features[0]; if (!feature.placeId) return; // Update the infowindow. const place = await feature.fetchPlace(); let content = '<span style="font-size:small">Display name: ' + place.displayName + '<br/> Place ID: ' + feature.placeId + '<br/> Feature type: ' + feature.featureType + '</span>'; updateInfoWindow(content, event.latLng); } // Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: '#810FCB', strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: 'white', fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: '#810FCB', fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; } // Helper function to create an info window. function updateInfoWindow(content, center) { infoWindow.setContent(content); infoWindow.setPosition(center); infoWindow.open({ map, shouldFocus: false, }); } initMap();
JavaScript
let map; let featureLayer; let infoWindow; let lastInteractedFeatureIds = []; let lastClickedFeatureIds = []; function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map((f) => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map((f) => f.placeId); featureLayer.style = applyStyle; } async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps"); map = new Map(document.getElementById("map"), { center: { lat: 39.23, lng: -105.73 }, zoom: 8, // In the cloud console, configure your Map ID with a style that enables the // 'Administrative Area Level 2' Data Driven Styling type. mapId: "a3efe1c035bad51b", // Substitute your own map ID. mapTypeControl: false, }); // Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer("ADMINISTRATIVE_AREA_LEVEL_2"); // Add the event listeners for the feature layer. featureLayer.addListener("click", handleClick); featureLayer.addListener("mousemove", handleMouseMove); // Map event listener. map.addListener("mousemove", () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } }); // Create the infowindow. infoWindow = new InfoWindow({}); // Apply style on load, to enable clicking. featureLayer.style = applyStyle; } // Helper function for the infowindow. async function createInfoWindow(event) { let feature = event.features[0]; if (!feature.placeId) return; // Update the infowindow. const place = await feature.fetchPlace(); let content = '<span style="font-size:small">Display name: ' + place.displayName + "<br/> Place ID: " + feature.placeId + "<br/> Feature type: " + feature.featureType + "</span>"; updateInfoWindow(content, event.latLng); } // Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: "#810FCB", strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: "white", fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: "#810FCB", fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; } // Helper function to create an info window. function updateInfoWindow(content, center) { infoWindow.setContent(content); infoWindow.setPosition(center); infoWindow.open({ map, shouldFocus: false, }); } 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>Handle Region Boundary Click Event</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: "weekly"});</script> </body> </html>