我正在使用在http://exploregooglemaps.blogspot.com.br/2012/02/measuring-distance-with-markers.html找到的一些有用代码来添加标记和测量距离。
我希望标记在默认情况下捕捉到道路，但是当用户按住 shift 键时，会使用直线。
我已经设法为 shift 键实现了 if 语句，当我按住 shift 键时会绘制一条路径，但是默认情况下不会绘制到道路路径的捕捉。
我正在调用两个函数，一个用于绘制直线drawPath，另一个用于绘制与道路线drawPathD的对齐
任何帮助将非常感激。
<code>
var map,
service = new google.maps.DirectionsService(),
shiftPressed = false,
poly;
var path = [];
shiftPressed = false;
var markers = [];
var routePoints = [];
google.maps.event.addDomListener(document, "keydown", function () {
shiftPressed = true;
});
google.maps.event.addDomListener(document, "keyup", function () {
shiftPressed = false;
});
function $(id) {
return document.getElementById(id);
}
var map;
var mapOptions = {
center: new google.maps.LatLng(-23.5489433, - 46.6388182),
zoom: 15,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var markers = [];
var line;
function initialize() {
map = new google.maps.Map($("map_canvas"), mapOptions);
line = new google.maps.Polyline({
map: map,
strokeColor: "#FF3333",
strokeOpacity: 0.5,
strokeWeight: 8
});
google.maps.event.addListener(map, 'click', function (event) {
var marker = new google.maps.Marker({
map: map,
position: event.latLng,
draggable: true
});
if (shiftPressed) {
markers.push(marker);
drawPath();
} else {
markers.push(marker);
drawPathD();
}
google.maps.event.addListener(marker, 'dblclick', function (event) {
marker.setMap(null);
drawPath();
});
google.maps.event.addListener(marker, 'drag', function (event) {
drawPath();
});
});
}
function countMarkers() {
count = 0;
for (var i = routePoints.length - 1; i >= 0; i--) {
if (markers[i].getMap() == null) {
routePoints.splice(i, 1);
} else {
count++;
}
}
return count;
}
function drawPath() {
countMarkers();
var coords = [];
for (var i = 0; i < markers.length; i++) {
coords.push(markers[i].getPosition());
}
line.setPath(coords);
meters = google.maps.geometry.spherical.computeLength(coords);
$("distKm").value = Math.round(meters / 1000 * 100) / 100;
$("distMi").value = Math.round(meters / 1609 * 100) / 100;
}
function drawPathD(event) {
countMarkers();
var coords = [];
service.route({
origin: path[path.length - 1],
destination: event.latLng,
travelMode: google.maps.DirectionsTravelMode.WALKING
}, function (result, status) {
if (status == google.maps.DirectionsStatus.OK) {
path = path.concat(result.routes[0].overview_path);
routePoints.setPath(path);
}
});
meters = google.maps.geometry.spherical.computeLength(coords);
$("distKm").value = Math.round(meters / 1000 * 100) / 100;
$("distMi").value = Math.round(meters / 1609 * 100) / 100;
}
function clearMarkers() {
for (var i = 0; i < markers.length; i++) {
markers[i].setMap(null)
}
drawPath();
}
google.maps.event.addDomListener(window, 'load', initialize);
</code>