geojson 文件格式问题，更大的坐标数组中的迷你数组（坐标）答案

【问题标题】：geojson file formatting issue, mini-arrays(coordinates) inside larger array of coordinatesgeojson 文件格式问题，更大的坐标数组中的迷你数组（坐标）
【发布时间】：2017-08-12 19:04:40
【问题描述】：

我的 geoJSON 文件：坐标键包含带有坐标的普通数组，但随后包含一个填充了更多坐标的迷你数组的数组。我无法遍历文件以提取路线的中心，以便将我的 google 功能层添加到我的 google api 调用中。

当我尝试拆分迷你阵列并将其添加到整个总阵列时，路线变得可见，但不正确。路线越过水面并穿过建筑物，它不知道顺序。任何帮助都会很棒。粗体打破了整个特征的格局。

例如： {"type":"Feature","properties":{"OBJECTID":3,"LENGTH":3919.4410000000003,"NAME":"Anacostia Riverwalk-SW","STATUS":"Open","MAINTENANC":" DDOT","Shape_Length":1194.6479669066844,"MILES":0.7423183712121213},"geometry":{"type":"MultiLineString","coordinates":[[[-77.02215895389972,38.87673054256091],[-77.02186869854079,38.87653957420972],[ -77.02150193815677,38.87588299990856],[-77.0208280524279,38.874621556490816],[-77.02075697415529,38.87448850380858],[-77.02062323938105,38.874211704408985],[-77.02008845385471,38.87338800912766],[-77.01937789804083,38.87202111748801],[-77.01768265826789,38.87204526498413]],

[[-77.02594024042205,38.87974434948391],[-77.02509229875858,38.87909983220277],[-77.0237707432032,38.8780375415248],[-77.02215132050688,38.87674248295079]] ]}}，

【问题讨论】：

标签： javascript ruby-on-rails google-maps-api-3 geojson

【解决方案1】：

你所说的mini-arrays只是geojson MultiLineStrings的规范。 http://geojson.org/geojson-spec.html#multilinestring

For type "MultiLineString", the "coordinates" member is an array of LineString coordinate arrays.

所以每个数组都描述了一条线的一部分，它们一起形成了结果路线。您可以使用 2 个 for 循环（它是一个数组数组）来迭代它们

var geojson = {
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "type": "MultiLineString","coordinates":[
          [[-77.02215895389972,38.87673054256091],[-77.02186869854079,38.87653957420972],[-77.02150193815677,38.87588299990856],[-77.0208280524279,38.874621556490816],[-77.02075697415529,38.87448850380858],[-77.02062323938105,38.874211704408985],[-77.02008845385471,38.87338800912766],[-77.01937789804083,38.87202111748801],[-77.01768265826789,38.87204526498413]],
          [[-77.02594024042205,38.87974434948391],[-77.02509229875858,38.87909983220277],[-77.0237707432032,38.8780375415248],[-77.02215132050688,38.87674248295079]] 
        ]
      }
    }
  ]
}

let coords = geojson.features[0].geometry.coordinates;
for (let i = 0; i < coords.length; i += 1) {
  for (let j = 0; j < coords[i].length; j += 1) {
    console.log(coords[i][j]);
  }
}

【讨论】：