其核心是找到LatLngs 之间的像素距离。然后在添加每个标记之前检查它与任何现有标记之间的像素距离。如果附近有另一个标记添加到标题,否则创建一个新标记。jsFiddle
function init() {
var mapOptions = {
center: new google.maps.LatLng(0, -0),
zoom: 4,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById('map-canvas'),mapOptions);
// to get the pixel position from the latlng
// https://stackoverflow.com/questions/1538681/how-to-call-fromlatlngtodivpixel-in-google-maps-api-v3
var overlay = new google.maps.OverlayView();
overlay.draw = function() {};
overlay.setMap(map);
google.maps.event.addListenerOnce(map, 'idle', function() {
if (overlay.getProjection()) {
var points = [
{ latlng: new google.maps.LatLng(40, -100), title: '1' },
{ latlng: new google.maps.LatLng(40.125, -100.125), title: '2' },
{ latlng: new google.maps.LatLng(40.25, -100.25), title: '3' },
{ latlng: new google.maps.LatLng(40.5, -100.5), title: '4' },
{ latlng: new google.maps.LatLng(40.75, -100.75), title: '5' },
{ latlng: new google.maps.LatLng(41, -101), title: '6' },
{ latlng: new google.maps.LatLng(35, -95), title: '7' },
{ latlng: new google.maps.LatLng(45, 105), title: '8' },
{ latlng: new google.maps.LatLng(25, -115), title: '9' },
{ latlng: new google.maps.LatLng(55, -85), title: '10' },
{ latlng: new google.maps.LatLng(30, -34), title: '11' }
];
// for each point
var markers = [];
points.forEach(function (point) {
var nearby = false;
var pointPixelPosition = overlay.getProjection().fromLatLngToContainerPixel(point.latlng);
markers.forEach(function(marker) {
var markerPixelPosition = overlay.getProjection().fromLatLngToContainerPixel(marker.getPosition());
// check for marker 'near by'
if (Math.abs(pointPixelPosition.x - markerPixelPosition.x) < 10 || Math.abs(pointPixelPosition.y - markerPixelPosition.y) < 10) {
nearby = true;
marker.setTitle(marker.getTitle() + ', ' + point.title);
}
});
// create new marker
if (!nearby) {
markers.push(new google.maps.Marker({ map: map, position: point.latlng, title: point.title }));
}
});
}
map.setCenter(new google.maps.LatLng(39.8282, -98.5795));
});
}