访问嵌套 JSON 文件中的坐标

Question

我正在尝试访问嵌套 JSON 文件中多边形的纬度/经度，并尝试使用 new google.maps.Polygon() 绘制它们，但遇到了一些麻烦。

UPDATE-2：我可以绘制多边形，但它只绘制第一个多边形，而不是全部 3：http://jsfiddle.net/vprbqaLm/10/

更新：在这里查看我最新的 JSFiddle：http://jsfiddle.net/vprbqaLm/9/ 现在我似乎无法读取坐标，因为我收到以下错误：Uncaught TypeError: Cannot read property 'coordinates' of undefined

我的代码如下所示：

var coords = data.features.geometry.coordinates;
var paths = [];
for (i = 0; i < coords.length; i++) {
    for (j = 0; j < coords[i].length; j++) {
        var path = [];
        for (k = 0; k < coords[i][j].length; k++) {
            var ll = new google.maps.LatLng(coords[i][j][k][1], coords[i][j][k][0]);
            path.push(ll);
        }
        paths.push(path);
    }
}
var polygon = new google.maps.Polygon({
    paths: paths,
    strokeColor: "#FF7800",
    strokeOpacity: 1,
    strokeWeight: 5,
    fillColor: "#46461F",
    fillOpacity: 1
});
return polygon;

这是示例 JSON 文件：

    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]
                ]
            ]
        }
    }]
};

Answer 1

两个建议

first:: 你可以在没有

的情况下分配坐标

  $.each(polygons, function (i, n) {
   .....
  }

你已经有了 javascrip 格式的坐标[[......],[.....]]，那么你不需要重新分配给paths[]

第二个似乎你有一个嵌套的 [] 对你的格式进行了很多尝试，然后是一个负嵌套级别。

JSON 坐标文字示例：

[[{"lat": 41.650299987709538, "lng": 12.536399034779624}, {"lat": 41.650331001957937, "lng": 12.53657301029202}, {"lat": 41.650344029686487, "lng": 12.537146999950506}, {"lat": 41.650474995651187 , "lng": 12.537842047638419}, {"lat": 41.650461970948285, "lng": 12.538146026115472}, {"lat": 41.65040398326272, "lng": 12.538020010393916}, {"lat": 41.650271995260688, "lng": 12.537231036701897}, {"lat": 41.650243023870289, "lng": 12.536492993378628}, {"lat": 41.650299987709538, "lng": 12.536399034779624}]]

如果您可以按照示例中的格式进行格式化，则可以进行直接分配，否则您必须转换坐标中的每对数字，将它们添加到数组中，然后将其分配给路径。