尝试从 geojson 文件中绘制多个多边形时，我真的很痛苦。下面我粘贴了 geojson 文件的示例以及用于访问它的 javascript。看来我遇到的主要问题是我无法进入每个记录中嵌套的坐标数组，因为它要么返回“坐标”未定义的错误，要么没有未定义的方法“setMap”。我已经能够返回类似 JSON 文件的其他嵌套方面(这是一个测试文件，真实的文件实际上有数据，只是试图在此处获取多边形绘图)，但获取这些坐标不起作用。我不是 javascript 大师，所以我无法判断代码在哪里无法进行正确的访问。
提前致谢。
json 数据如下所示:
var data={
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"id": 1,
"properties": {
"Name": "",
"description": "",
"timestamp": "",
"begin": "",
"end": "",
"altitudeMode": "clampToGround",
"tessellate": 1,
"extrude": -1,
"visibility": -1
},
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
-83.126571,
42.348706
],
[
-83.126520,
42.348634
],
[
-83.126516,
42.348635
],
[
-83.126147,
42.348778
],
[
-83.126144,
42.348780
],
[
-83.126195,
42.348852
],
[
-83.126199,
42.348851
],
[
-83.126568,
42.348708
],
[
-83.126571,
42.348706
]
]
]
}
},
{
"type": "Feature",
"id": 2,
"properties": {
"Name": "",
"description": "",
"timestamp": "",
"begin": "",
"end": "",
"altitudeMode": "clampToGround",
"tessellate": 1,
"extrude": -1,
"visibility": -1
},
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
-83.132805,
42.356496
],
[
-83.132753,
42.356423
],
[
-83.132751,
42.356424
],
[
-83.132243,
42.356624
],
[
-83.132241,
42.356625
],
[
-83.132294,
42.356698
],
[
-83.132296,
42.356697
],
[
-83.132802,
42.356497
],
[
-83.132805,
42.356496
]
]
]
}
},
{
"type": "Feature",
"id": 3,
"properties": {
"Name": "",
"description": "",
"timestamp": "",
"begin": "",
"end": "",
"altitudeMode": "clampToGround",
"tessellate": 1,
"extrude": -1,
"visibility": -1
},
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
-83.126776,
42.351813
],
[
-83.126492,
42.351413
],
[
-83.126189,
42.351525
],
[
-83.126191,
42.351528
],
[
-83.126376,
42.351807
],
[
-83.126776,
42.351813
]
]
]
}
}
etc...
]
}
我得到了如下的 javascript，使用 geojason.info 中使用的示例:http://demos.geojason.info/complex-geojson-polygons-google-maps-demo.php
var points;
var pointsMore;
var polygon;
var map;
function initializeMap() {
map = new google.maps.Map(document.getElementById("map_canvas"), {
zoom: 11,
center: new google.maps.LatLng(42.347727, -83.058014),
mapTypeId: google.maps.MapTypeId.TERRAIN
});
var polygon = createPolygons(pointsMore);
//this is where the problem is...check nesting.
polygon.setMap(map);
}
function createPolygons(pointsMore) {
for (var y = 0; y < data.features.length; y++) {
var points = data.features[y];
for (var z = 0; points.geometry.length; z++) {
var pointsMore = points.geometry[z];
var coords = pointsMore.coordinates;
var paths = [];
$.each(coords,function(i,n){
$.each(n, function(j,o){
var path = [];
$.each(o,function(k,p){
var ll = new google.maps.LatLng(p[1],[0]);
path.push(ll);
});
paths.push(path);
});
});
var polygon = new google.maps.Polygon({
paths: paths,
strokeColor: "#FF7800",
strokeOpacity: 1,
strokeWeight: 2,
fillColor: "#46461F",
fillOpacity: 0.25
});
return polygon;
}
}
}
最佳答案
points.geometry 是一个对象，但您试图像数组一样循环遍历它。要访问坐标，请使用:
var coordinates = data.features[y].geometry.coordinates;
关于javascript - 访问嵌套 geojson 文件中的坐标以使用 Google Maps API v3 绘制多边形，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/7389811/