首先你需要告诉请求你想要替代路线，像这样
// for example
var request = {
origin: start,
destination: end,
provideRouteAlternatives: true,
travelMode: google.maps.TravelMode[DRIVING]
};
然后你有多个 response.routes 对象（注意，有时你只得到 1 个路由）。
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
for(var i in response.routes ) {
// ...
}
}
}
现在您可以使用 response.routes[i] 作为方向渲染的来源。
或者您制作自己的折线。使用 response.routes[i].overview_path 作为路径
var line = new google.maps.Polyline({
path: response.routes[i].overview_path,
strokeColor: "#ff0000", // you might want different colors per suggestion
strokeOpacity: 0.7,
strokeWeight: 3
});
line.setMap(map);
这是一个有效的示例。
只需更改您的 API 密钥即可。
如您所愿，点击路线会突出显示它
更新：我喜欢这种方式。
灰色线和彩色线都会生成。但突出显示仅显示地图上的 1 条建议。
灰色的大线很容易点击。所以它得到的是点击事件而不是彩色线。
这也是避免 Z-index 问题的最简单方法。
我存储数据（持续时间、距离），并在 infoWindow 上显示
<!DOCTYPE html>
<html>
<head>
<title>Google Map Direction Render Alternate Route How To Select Desired Path</title>
<meta name="viewport" content="initial-scale=1.0">
<meta charset="utf-8">
<style>
html, body {
height: 100%;
margin: 0;
padding: 0;
}
#map {
height: 90%;
}
</style>
</head>
<body>
<form id="form">
<input id="from" placeholder="From" value="Brussel" />
<input id="to" placeholder="To" value="Antwerpen" />
<input type="submit" value="GO" />
</form>
<div id="map"></div>
<div id="info">
<a href="http://stackoverflow.com/questions/39264760/google-map-direction-render-alternate-route-how-to-select-desired-path/39268344#39268344">Stackoverflow</a>
</div>
<script type="text/javascript" src="https://maps.google.com/maps/api/js?key=YOUR_API_KEY&libraries=geometry"></script>
<script>
var map;
var directionsService;
var polylines = [];
var shadows = [];
var data = [];
var infowindow;
function initMap() {
map = new google.maps.Map(document.getElementById('map'), {
center: {lat: 50.84659376378408, lng: 4.3531406857355215},
zoom: 12,
mapTypeId: 'terrain'
});
google.maps.event.addDomListener(document.getElementById('form'), 'submit', function(e) {
calcRoute(
document.getElementById('from').value,
document.getElementById('to').value
);
// prevent the form from really submitting
e.preventDefault();
return false;
});
directionsService = new google.maps.DirectionsService();
// get the bounds of the polyline
// http://stackoverflow.com/questions/3284808/getting-the-bounds-of-a-polyine-in-google-maps-api-v3
google.maps.Polyline.prototype.getBounds = function(startBounds) {
if(startBounds) {
var bounds = startBounds;
}
else {
var bounds = new google.maps.LatLngBounds();
}
this.getPath().forEach(function(item, index) {
bounds.extend(new google.maps.LatLng(item.lat(), item.lng()));
});
return bounds;
};
}
// this function calculates multiple suggested routes.
// We will draw 3 (broad stroke) suggested routs in grey. These are broad to click on them easier.
// We duplicate these routes with a thin, colored line; only route 0 is shown.
function calcRoute(start, end) {
var request = {
origin: start,
destination: end,
provideRouteAlternatives: true,
unitSystem: google.maps.UnitSystem.METRIC,
travelMode: google.maps.TravelMode['DRIVING']
};
directionsService.route(request, function(response, status) {
// clear former polylines
for(var j in polylines ) {
polylines[j].setMap(null);
shadows[j].setMap(null);
}
polylines = [];
shadows = [];
data = [];
if (status == google.maps.DirectionsStatus.OK) {
var bounds = new google.maps.LatLngBounds();
for(var i in response.routes) {
// let's make the first suggestion highlighted;
var hide = (i==0 ? false : true);
var shadow = drawPolylineShadow(response.routes[i].overview_path, '#666666');
var line = drawPolyline(response.routes[i].overview_path, '#0000ff', hide);
polylines.push(line);
shadows.push(shadow);
// let's add some data for the infoWindow
data.push({
distance: response.routes[i].legs[0].distance,
duration: response.routes[i].legs[0].duration,
end_address: response.routes[i].legs[0].end_address,
start_address: response.routes[i].legs[0].start_address,
end_location: response.routes[i].legs[0].end_location,
start_location: response.routes[i].legs[0].start_location
});
bounds = line.getBounds(bounds);
google.maps.event.addListener(shadow, 'click', function(e) {
// detect which route was clicked on
var index = shadows.indexOf(this);
highlightRoute(index, e);
});
}
map.fitBounds(bounds);
}
});
}
// this makes one of the colored routes visible.
function highlightRoute(index, e) {
for(var j in polylines ) {
if(j==index) {
//var color = '#0000ff';
polylines[j].setMap(map);
// feel free to customise this string
var contentString =
'<span>'+ data[j].distance.text +'</span><br/>'+
'<span>'+ data[j].duration.text +'</span><br/>'+
'<span>route: '+ j +'</span><br/>'+
//'From: <span>'+ data[j].start_address +'</span><br/>'+
//'To: <span>'+ data[j].end_address +'</span><br/>'+
'';
if(e) {
var position = new google.maps.LatLng(e.latLng.lat(), e.latLng.lng());
// it may be needed to close the previous infoWindow
if(infowindow) {
infowindow.close();
infowindow = null;
}
infowindow = new google.maps.InfoWindow({
content: contentString,
position: position,
map: map
});
//infowindow.open(map, polylines[j]);
}
}
else {
polylines[j].setMap(null);
}
}
}
// returns a polyline.
// if hide is set to true, the line is not put on the map
function drawPolyline(path, color, hide) {
var line = new google.maps.Polyline({
path: path,
strokeColor: color,
strokeOpacity: 0.9,
strokeWeight: 3
});
if(! hide) {
line.setMap(map);
}
return line;
}
function drawPolylineShadow(path, color, hide) {
var line = new google.maps.Polyline({
path: path,
strokeColor: color,
strokeOpacity: 0.4,
strokeWeight: 7
});
if(! hide) {
line.setMap(map);
}
return line;
}
google.maps.event.addDomListener(window, 'load', initMap);
</script>
</body>
</html>
较早的代码。这会改变折线的颜色
<!DOCTYPE html>
<html>
<head>
<title>Suggested routes</title>
<meta name="viewport" content="initial-scale=1.0">
<meta charset="utf-8">
<style>
html, body {
height: 100%;
margin: 0;
padding: 0;
}
#map {
height: 90%;
}
</style>
</head>
<body>
<form id="form">
<input id="from" placeholder="From" value="Brussel" />
<input id="to" placeholder="To" value="Antwerpen" />
<input type="submit" value="GO" />
</form>
<div id="map"></div>
<script type="text/javascript" src="https://maps.google.com/maps/api/js?key=YOUR_API_KEY&libraries=geometry"></script>
<script>
var map;
var directionsService;
var polylines = [];
function initMap() {
map = new google.maps.Map(document.getElementById('map'), {
center: {lat: 50.84659376378408, lng: 4.3531406857355215},
zoom: 12,
mapTypeId: 'terrain'
});
google.maps.event.addDomListener(document.getElementById('form'), 'submit', function(e) {
calcRoute(
document.getElementById('from').value,
document.getElementById('to').value
);
// prevent the form from really submitting
e.preventDefault();
return false;
});
directionsService = new google.maps.DirectionsService();
// get the bounds of the polyline
// http://stackoverflow.com/questions/3284808/getting-the-bounds-of-a-polyine-in-google-maps-api-v3
google.maps.Polyline.prototype.getBounds = function(startBounds) {
if(startBounds) {
var bounds = startBounds;
}
else {
var bounds = new google.maps.LatLngBounds();
}
this.getPath().forEach(function(item, index) {
bounds.extend(new google.maps.LatLng(item.lat(), item.lng()));
});
return bounds;
};
}
function calcRoute(start, end) {
var request = {
origin: start,
destination: end,
provideRouteAlternatives: true,
unitSystem: google.maps.UnitSystem.METRIC,
travelMode: google.maps.TravelMode['DRIVING']
};
directionsService.route(request, function(response, status) {
// clear former polylines
for(var j in polylines ) {
polylines[j].setMap(null);
}
polylines = [];
if (status == google.maps.DirectionsStatus.OK) {
var bounds = new google.maps.LatLngBounds();
// draw the lines in reverse orde, so the first one is on top (z-index)
for(var i=response.routes.length - 1; i>=0; i-- ) {
// let's make the first suggestion highlighted;
if(i==0) {
var color = '#0000ff';
}
else {
var color = '#999999';
}
var line = drawPolyline(response.routes[i].overview_path, color);
polylines.push(line);
bounds = line.getBounds(bounds);
google.maps.event.addListener(line, 'click', function() {
// detect which route was clicked on
var index = polylines.indexOf(this);
highlightRoute(index);
});
}
map.fitBounds(bounds);
}
});
}
function highlightRoute(index) {
for(var j in polylines ) {
if(j==index) {
var color = '#0000ff';
}
else {
var color = '#999999';
}
polylines[j].setOptions({strokeColor: color});
}
}
function drawPolyline(path, color) {
var line = new google.maps.Polyline({
path: path,
strokeColor: color,
strokeOpacity: 0.7,
strokeWeight: 3
});
line.setMap(map);
return line;
}
google.maps.event.addDomListener(window, 'load', initMap);
</script>
</body>
</html>