我想从geoJSON文件加载行程。 目前，它有效，但只有两点。
但我需要添加4或5个航点。我的代码只读取了两个第一点并将它们设置为Origin和destination。
这是我的代码
google.maps.event.addListener(map.data, 'addfeature', function (e) {
if (e.feature.getGeometry().getType() === 'Point') {
map.setCenter(e.feature.getGeometry().get());
if (!origin) origin = e.feature.getGeometry().get(); //if origin does not exist
else if (!destination) {
destination = e.feature.getGeometry().get();
calculate();
}
}
});
有什么想法吗？ 我必须创建一个循环吗？ 或者更改航点的json代码？
这是我的json：
{
"type": "FeatureCollection",
"features":
[
{ "type": "Feature",
"geometry": {"type": "Point", "coordinates": [-73.562686, 45.4960413]},
"properties": {"prop0": "value0"}
},
{ "type": "Feature",
"geometry": {"type": "Point", "coordinates": [-73.568367, 45.4933086]},
"properties": {"prop0": "value0"}
}
]
}
谢谢！
答案 0 :(得分：1)
function calculate() {
var request = {
origin: origin,
waypoints: waypts,
destination: destination,
travelMode: google.maps.TravelMode.DRIVING
};
directionsDisplay.setPanel(document.getElementById('directions-panel'));
directionsService.route(request, function (response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
}
});
}
// global variables
var origin = null;
var destination = null;
var waypts = [];
var infowindow = new google.maps.InfoWindow();
var directionsDisplay = new google.maps.DirectionsRenderer();
var directionsService = new google.maps.DirectionsService();
function initialize() {
// Create a simple map.
features = [];
map = new google.maps.Map(document.getElementById('map-canvas'), {
zoom: 4,
center: {
lat: -28,
lng: 137.883
}
});
directionsDisplay.setMap(map);
directionsDisplay.setPanel(document.getElementById('directions-panel'));
google.maps.event.addListener(map, 'click', function () {
infowindow.close();
});
// process the loaded GeoJSON data.
google.maps.event.addListener(map.data, 'addfeature', function (e) {
if (e.feature.getGeometry().getType() === 'Point') {
map.setCenter(e.feature.getGeometry().get());
// set the origin to the first point
if (!origin) origin = e.feature.getGeometry().get();
// set the destination to the second point
else waypts.push({
location: e.feature.getGeometry().get(),
stopover: true
});
// calculate the directions once both origin and destination are set
// calculate();
}
});
google.maps.event.addListenerOnce(map, 'idle', function () {
if (!destination) {
destination = waypts.pop();
destination = destination.location;
// calculate the directions once both origin and destination are set
calculate();
}
});
map.data.addGeoJson(data);
}
google.maps.event.addDomListener(window, 'load', initialize);
要解决Dr.Molle关于在加载数据层之前触发idle事件的观点，您可以创建自定义data_idle事件，并在所有点之后触发该事件。 GeoJson已经处理完毕。
var features_added = 0;
function initialize() {
// Create a simple map.
features = [];
map = new google.maps.Map(document.getElementById('map-canvas'), {
zoom: 4,
center: {
lat: -28,
lng: 137.883
}
});
directionsDisplay.setMap(map);
directionsDisplay.setPanel(document.getElementById('directions-panel'));
google.maps.event.addListener(map, 'click', function () {
infowindow.close();
});
// process the loaded GeoJSON data.
google.maps.event.addListener(map.data, 'addfeature', function (e) {
if (e.feature.getGeometry().getType() === 'Point') {
features_added++;
map.setCenter(e.feature.getGeometry().get());
// set the origin to the first point
if (!origin) origin = e.feature.getGeometry().get();
// set the destination to the second point
else waypts.push({
location: e.feature.getGeometry().get(),
stopover: true
});
setTimeout(function() {features_added--; if (features_added <= 0) google.maps.event.trigger(map, 'data_idle');
}, 500);
}
});
google.maps.event.addListenerOnce(map, 'data_idle', function () {
if (!destination) {
destination = waypts.pop();
destination = destination.location;
// calculate the directions once both origin and destination are set
calculate();
}
});
map.data.loadGeoJson("http://www.geocodezip.com/directions.json.txt");
}
google.maps.event.addDomListener(window, 'load', initialize);
答案 1 :(得分：0)
问题是您无法访问功能所属的FeatureCollection。在解析geoJSON时，也没有事件会触发（当addfeature-event触发时你永远不会知道它是否是特定FeatureCollection的最后一次）
您可以存储功能的其他属性，例如航点数量。
sample-JSON（包括定义的其他属性，例如，如果某个点是航点，起点或目的地，或者当它是航点的航点时）
{
"type": "FeatureCollection",
"features": [
{
"type" : "Feature",
"properties" : {route :{"id" :1,
"type" :"origin",
"points":2
}
},
"geometry" : {"type" : "Point",
"coordinates":[8.528849, 52.030656]}
},
{
"type" : "Feature",
"properties" : {route :{"id" :1,
"type" :"destination",
"points":2
}
},
"geometry" : {"type" : "Point",
"coordinates":[11.5819, 48.1351253]}
},
{
"type": "Feature",
"properties" : {"route" :{"id" :1,
"type" :"waypoint",
"index" :1,
"points":2
}
},
"geometry" : {"type" : "Point",
"coordinates":[13.40495,52.52]}
},
{
"type" : "Feature",
"properties" : {route :{"id":1,
"type":"waypoint",
"index":0,
"points":2
}
},
"geometry" : {"type" : "Point",
"coordinates":[9.99368, 53.5510846]}
}
]}
它将属性存储在自定义route - 属性中。
属性是：
type（出发地，目的地或航路点）id（路线的一些唯一ID，通过使用您可以定义多条路线的ID）points（为路线定义的航点数）index ...用于类型：waypoint（waypoints-array中航路点的索引，从0开始）解析这些属性：
map.data.addListener('addfeature',function(e){
var geo= e.feature.getGeometry();
if(geo.getType()==='Point' && e.feature.getProperty('route')){
var id = e.feature.getProperty('route').id,
type = e.feature.getProperty('route').type,
points= e.feature.getProperty('route').points,
data;
//the routes will be stored as a property of map.data
if(!map.data.get('routes')){
map.data.set('routes',{});
}
if(!map.data.get('routes')[id]){
map.data.get('routes')[id]={waypoints:[],points:points,origin:null,destination:null};
}
data= map.data.get('routes')[id];
switch(type){
case 'waypoint':
data.points--;
data.waypoints[e.feature.getProperty('route').index]={location:geo.get()};
break;
default:
data[type]= geo.get();
}
if(!data.points && data.origin && data.destination){
//parsing of the route is complete
delete data.points;
//run the callback,
//data is an object suitable to be used as DirectionsRequest
//you only need to add the desired travelMode
callback(data);
}
}
});