有没有办法以字符串格式获取谷歌地图多边形坐标值

Question

这就是我绘制多边形的方式。我希望它获取绘制的多边形区域，并在下一页的地图上标记位于绘制的多边形区域下方的属性，并在其上绘制多边形。我正在获取多边形的坐标，但很难将 url 上的坐标发送到下一页。

var map = new google.maps.Map(document.getElementById('map'), {
center: {lat: -34.397, lng: 150.644},
zoom: 8
});
var drawingManager = new google.maps.drawing.DrawingManager({
drawingMode: google.maps.drawing.OverlayType.POLYGON,
drawingControl: true,
drawingControlOptions: {
position: google.maps.ControlPosition.TOP_CENTER,
drawingModes: [ 'polygon']
},
markerOptions: {icon: 'https://developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png'},
polygonOptions: {
editable: true
}
});
google.maps.event.addListener(drawingManager, 'overlaycomplete', function(event) {
$.each(event.overlay.getPath().getArray(), function(key, latlng){
var lat = latlng.lat();
var lon = latlng.lng();
console.log(lat, lon); 
console.log(latlng); //do something with the coordinates
lats.push({lat:lat,lon:lon});
var latlng = {lat: parseFloat(lat), lng: parseFloat(lon)};
geocoder.geocode({'location': latlng}, function(results, status) {
if (status === 'OK') {
if (results[0]) {
var t = results[0].formatted_address.split(',');
var country = t[t.length-1];
var state = t[t.length-2];
locations.push({'state':state,country:country});
//  console.log(locations);
//  console.log(lats);
// locations.push({'state:'lat,lon});
} else {
window.alert('No results found');
}
} else {
window.alert('Geocoder failed due to: ' + status);
}
});
});

Answer 1

我可以建议使用编码路径，以便在下一页的URL中将多边形作为字符串参数发送。Maps JavaScript API具有几何库，允许将LatLng数组编码和解码为字符串：

https://developers.google.com/maps/documentation/javascript/reference/3/geometry#encoding

你可以使用类似的东西

google.maps.event.addListener(drawingManager, 'overlaycomplete', function(event) {
var encodedPath = google.maps.geometry.encoding.encodePath(event.overlay.getPath());
window.open(m_url + "?path="+encodedPath, "restore polygon"); 
});

在带有绘图管理器的页面中，并在下一页上将 LatLng 数组恢复为

let params = (new URL(document.location)).searchParams;
let encodedPath = params.get("path");
if (encodedPath) {
var path = google.maps.geometry.encoding.decodePath(encodedPath);
var polygon = new google.maps.Polygon({
paths: path,
map: map
});
}

概念验证

var map;
function initMap() {
map = new google.maps.Map(document.getElementById('map'), {
center: {lat: -34.397, lng: 150.644},
zoom: 8
});
var drawingManager = new google.maps.drawing.DrawingManager({
drawingMode: google.maps.drawing.OverlayType.POLYGON,
drawingControl: true,
drawingControlOptions: {
position: google.maps.ControlPosition.TOP_CENTER,
drawingModes: [ 'polygon']
},
markerOptions: {
icon: 'https://developers.google.com/maps/documentation/javascript/examples/full/images/beachflag.png'},
polygonOptions: {
editable: true
},
map: map
});
google.maps.event.addListener(drawingManager, 'overlaycomplete', function(event) {
var encodedPath = google.maps.geometry.encoding.encodePath(event.overlay.getPath());
console.log(encodedPath);
window.open("http://output.jsbin.com/hicomid?path="+encodedPath, "restore polygon"); 
});
}

#map {
height: 100%;
}
html, body {
height: 100%;
margin: 0;
padding: 0;
}

<div id="map"></div>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDztlrk_3CnzGHo7CFvLFqE_2bUKEq1JEU&libraries=drawing,geometry&callback=initMap"
async defer></script>

你也可以在jsfiddle上查看这个例子：https://jsfiddle.net/xomena/tpvoL426/

我希望这有帮助！