Panoramica
Scopri come creare una legenda su una mappa Google con questo tutorial. In genere le legende descrivono i simboli e gli indicatori su una mappa. Puoi crearli utilizzando la funzionalità di posizionamento dei controlli personalizzati.
La mappa di seguito contiene una legenda che fornisce informazioni su tre diversi indicatori personalizzati sulla mappa.
La sezione seguente mostra tutto il codice necessario per creare la mappa e la legenda in questo tutorial.
TypeScript
let map: google.maps.Map; function initMap(): void { map = new google.maps.Map(document.getElementById("map") as HTMLElement, { zoom: 16, center: new google.maps.LatLng(-33.91722, 151.23064), mapTypeId: "roadmap", }); const iconBase = "https://maps.google.com/mapfiles/kml/shapes/"; const icons: Record<string, any> = { parking: { name: "Parking", icon: iconBase + "parking_lot_maps.png", }, library: { name: "Library", icon: iconBase + "library_maps.png", }, info: { name: "Info", icon: iconBase + "info-i_maps.png", }, }; const features = [ { position: new google.maps.LatLng(-33.91721, 151.2263), type: "info", }, { position: new google.maps.LatLng(-33.91539, 151.2282), type: "info", }, { position: new google.maps.LatLng(-33.91747, 151.22912), type: "info", }, { position: new google.maps.LatLng(-33.9191, 151.22907), type: "info", }, { position: new google.maps.LatLng(-33.91725, 151.23011), type: "info", }, { position: new google.maps.LatLng(-33.91872, 151.23089), type: "info", }, { position: new google.maps.LatLng(-33.91784, 151.23094), type: "info", }, { position: new google.maps.LatLng(-33.91682, 151.23149), type: "info", }, { position: new google.maps.LatLng(-33.9179, 151.23463), type: "info", }, { position: new google.maps.LatLng(-33.91666, 151.23468), type: "info", }, { position: new google.maps.LatLng(-33.916988, 151.23364), type: "info", }, { position: new google.maps.LatLng(-33.91662347903106, 151.22879464019775), type: "parking", }, { position: new google.maps.LatLng(-33.916365282092855, 151.22937399734496), type: "parking", }, { position: new google.maps.LatLng(-33.91665018901448, 151.2282474695587), type: "parking", }, { position: new google.maps.LatLng(-33.919543720969806, 151.23112279762267), type: "parking", }, { position: new google.maps.LatLng(-33.91608037421864, 151.23288232673644), type: "parking", }, { position: new google.maps.LatLng(-33.91851096391805, 151.2344058214569), type: "parking", }, { position: new google.maps.LatLng(-33.91818154739766, 151.2346203981781), type: "parking", }, { position: new google.maps.LatLng(-33.91727341958453, 151.23348314155578), type: "library", }, ]; features.forEach((feature) => { new google.maps.Marker({ position: feature.position, icon: icons[feature.type].icon, map: map, }); }); const legend = document.getElementById("legend") as HTMLElement; for (const key in icons) { const type = icons[key]; const name = type.name; const icon = type.icon; const div = document.createElement("div"); div.innerHTML = '<img src="' + icon + '"> ' + name; legend.appendChild(div); } map.controls[google.maps.ControlPosition.RIGHT_BOTTOM].push(legend); } declare global { interface Window { initMap: () => void; } } window.initMap = initMap;
JavaScript
let map; function initMap() { map = new google.maps.Map(document.getElementById("map"), { zoom: 16, center: new google.maps.LatLng(-33.91722, 151.23064), mapTypeId: "roadmap", }); const iconBase = "https://maps.google.com/mapfiles/kml/shapes/"; const icons = { parking: { name: "Parking", icon: iconBase + "parking_lot_maps.png", }, library: { name: "Library", icon: iconBase + "library_maps.png", }, info: { name: "Info", icon: iconBase + "info-i_maps.png", }, }; const features = [ { position: new google.maps.LatLng(-33.91721, 151.2263), type: "info", }, { position: new google.maps.LatLng(-33.91539, 151.2282), type: "info", }, { position: new google.maps.LatLng(-33.91747, 151.22912), type: "info", }, { position: new google.maps.LatLng(-33.9191, 151.22907), type: "info", }, { position: new google.maps.LatLng(-33.91725, 151.23011), type: "info", }, { position: new google.maps.LatLng(-33.91872, 151.23089), type: "info", }, { position: new google.maps.LatLng(-33.91784, 151.23094), type: "info", }, { position: new google.maps.LatLng(-33.91682, 151.23149), type: "info", }, { position: new google.maps.LatLng(-33.9179, 151.23463), type: "info", }, { position: new google.maps.LatLng(-33.91666, 151.23468), type: "info", }, { position: new google.maps.LatLng(-33.916988, 151.23364), type: "info", }, { position: new google.maps.LatLng(-33.91662347903106, 151.22879464019775), type: "parking", }, { position: new google.maps.LatLng(-33.916365282092855, 151.22937399734496), type: "parking", }, { position: new google.maps.LatLng(-33.91665018901448, 151.2282474695587), type: "parking", }, { position: new google.maps.LatLng(-33.919543720969806, 151.23112279762267), type: "parking", }, { position: new google.maps.LatLng(-33.91608037421864, 151.23288232673644), type: "parking", }, { position: new google.maps.LatLng(-33.91851096391805, 151.2344058214569), type: "parking", }, { position: new google.maps.LatLng(-33.91818154739766, 151.2346203981781), type: "parking", }, { position: new google.maps.LatLng(-33.91727341958453, 151.23348314155578), type: "library", }, ]; features.forEach((feature) => { new google.maps.Marker({ position: feature.position, icon: icons[feature.type].icon, map: map, }); }); const legend = document.getElementById("legend"); for (const key in icons) { const type = icons[key]; const name = type.name; const icon = type.icon; const div = document.createElement("div"); div.innerHTML = '<img src="' + icon + '"> ' + name; legend.appendChild(div); } map.controls[google.maps.ControlPosition.RIGHT_BOTTOM].push(legend); } window.initMap = 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; } #legend { font-family: Arial, sans-serif; background: #fff; padding: 10px; margin: 10px; border: 3px solid #000; } #legend h3 { margin-top: 0; } #legend img { vertical-align: middle; }
HTML
<html> <head> <title>Custom Legend</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <div id="legend"><h3>Legend</h3></div> <!-- The `defer` attribute causes the callback to execute after the full HTML document has been parsed. For non-blocking uses, avoiding race conditions, and consistent behavior across browsers, consider loading using Promises. See https://developers.google.com/maps/documentation/javascript/load-maps-js-api for more information. --> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly" defer ></script> </body> </html>
Prova Sample
Le sezioni seguenti spiegano i passaggi principali per creare una legenda.
Creazione del container legenda
La tabella seguente spiega il codice che personalizza la legenda.
Codice e descrizione | |
---|---|
|
Crea un div per conservare i contenuti.Aggiunge un'intestazione di livello tre (3) a div . |
|
Posiziona div nella parte inferiore destra
della mappa aggiungendo una posizione di controllo. Scopri di più sulle altre opzioni di controllo relative alla posizione. |
|
Applica gli stili al controllo della legenda utilizzando CSS. |
Aggiunta dei contenuti della legenda
Utilizza la definizione degli stili degli indicatori esistenti per completare la legenda.
var legend = document.getElementById('legend');
for (var style in styles) {
var name = style.name;
var icon = style.icon;
var div = document.createElement('div');
div.innerHTML = '<img src="' + icon + '"> ' + name;
legend.appendChild(div);
}