问题
I am working on a website where I have to render a google map according to the design, I have a circle in map and its editable, I want to change the default rounded handles to some custom image icon. How can I do that, for reference this website has already done that.
回答1:
The website you reference is not using an editable circle, it is using MVC binding as shown in this example from this "article" in the documentation
example fiddle from this related question: How to style editable circle controls in Google Maps
code snippet:
function init() {
var mapDiv = document.getElementById('map-canvas');
var map = new google.maps.Map(mapDiv, {
center: new google.maps.LatLng(37.790234970864, -122.39031314844),
zoom: 8,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var distanceWidget = new DistanceWidget(map);
google.maps.event.addListener(distanceWidget, 'distance_changed', function() {
displayInfo(distanceWidget);
});
google.maps.event.addListener(distanceWidget, 'position_changed', function() {
displayInfo(distanceWidget);
});
}
google.maps.event.addDomListener(window, 'load', init);
/**
* A distance widget that will display a circle that can be resized and will
* provide the radius in km.
*
* @param {google.maps.Map} map The map on which to attach the distance widget.
*
* @constructor
*/
function DistanceWidget(map) {
this.set('map', map);
this.set('position', map.getCenter());
var marker = new google.maps.Marker({
draggable: true,
icon: {
url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
size: new google.maps.Size(7, 7),
anchor: new google.maps.Point(4, 4)
},
title: 'Move me!'
});
// Bind the marker map property to the DistanceWidget map property
marker.bindTo('map', this);
// Bind the marker position property to the DistanceWidget position
// property
marker.bindTo('position', this);
// Create a new radius widget
var radiusWidget = new RadiusWidget();
// Bind the radiusWidget map to the DistanceWidget map
radiusWidget.bindTo('map', this);
// Bind the radiusWidget center to the DistanceWidget position
radiusWidget.bindTo('center', this, 'position');
// Bind to the radiusWidgets' distance property
this.bindTo('distance', radiusWidget);
// Bind to the radiusWidgets' bounds property
this.bindTo('bounds', radiusWidget);
}
DistanceWidget.prototype = new google.maps.MVCObject();
/**
* A radius widget that add a circle to a map and centers on a marker.
*
* @constructor
*/
function RadiusWidget() {
var circle = new google.maps.Circle({
strokeWeight: 2
});
// Set the distance property value, default to 50km.
this.set('distance', 50);
// Bind the RadiusWidget bounds property to the circle bounds property.
this.bindTo('bounds', circle);
// Bind the circle center to the RadiusWidget center property
circle.bindTo('center', this);
// Bind the circle map to the RadiusWidget map
circle.bindTo('map', this);
// Bind the circle radius property to the RadiusWidget radius property
circle.bindTo('radius', this);
this.addSizer_();
}
RadiusWidget.prototype = new google.maps.MVCObject();
/**
* Update the radius when the distance has changed.
*/
RadiusWidget.prototype.distance_changed = function() {
this.set('radius', this.get('distance') * 1000);
};
/**
* Add the sizer marker to the map.
*
* @private
*/
RadiusWidget.prototype.addSizer_ = function() {
var sizer = new google.maps.Marker({
draggable: true,
icon: {
url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
size: new google.maps.Size(7, 7),
anchor: new google.maps.Point(4, 4)
},
title: 'Drag me!'
});
sizer.bindTo('map', this);
sizer.bindTo('position', this, 'sizer_position');
var me = this;
google.maps.event.addListener(sizer, 'drag', function() {
// Set the circle distance (radius)
me.setDistance();
});
};
/**
* Update the center of the circle and position the sizer back on the line.
*
* Position is bound to the DistanceWidget so this is expected to change when
* the position of the distance widget is changed.
*/
RadiusWidget.prototype.center_changed = function() {
var bounds = this.get('bounds');
// Bounds might not always be set so check that it exists first.
if (bounds) {
var lng = bounds.getNorthEast().lng();
// Put the sizer at center, right on the circle.
var position = new google.maps.LatLng(this.get('center').lat(), lng);
this.set('sizer_position', position);
}
};
/**
* Calculates the distance between two latlng locations in km.
* @see http://www.movable-type.co.uk/scripts/latlong.html
*
* @param {google.maps.LatLng} p1 The first lat lng point.
* @param {google.maps.LatLng} p2 The second lat lng point.
* @return {number} The distance between the two points in km.
* @private
*/
RadiusWidget.prototype.distanceBetweenPoints_ = function(p1, p2) {
if (!p1 || !p2) {
return 0;
}
var R = 6371; // Radius of the Earth in km
var dLat = (p2.lat() - p1.lat()) * Math.PI / 180;
var dLon = (p2.lng() - p1.lng()) * Math.PI / 180;
var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(p1.lat() * Math.PI / 180) * Math.cos(p2.lat() * Math.PI / 180) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
var d = R * c;
return d;
};
/**
* Set the distance of the circle based on the position of the sizer.
*/
RadiusWidget.prototype.setDistance = function() {
// As the sizer is being dragged, its position changes. Because the
// RadiusWidget's sizer_position is bound to the sizer's position, it will
// change as well.
var pos = this.get('sizer_position');
var center = this.get('center');
var distance = this.distanceBetweenPoints_(center, pos);
// Set the distance property for any objects that are bound to it
this.set('distance', distance);
};
function displayInfo(widget) {
var info = document.getElementById('info');
info.innerHTML = 'Position: ' + widget.get('position').toUrlValue(3) + ', distance: ' + widget.get('distance').toFixed(3);
}html,
body,
#map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}<script src="https://maps.googleapis.com/maps/api/js?v=3&libraries=geometry"></script>
<div id="info"></div>
<div id="map-canvas"></div>来源：https://stackoverflow.com/questions/19876523/google-map-circle-change-edit-handle-icon