GeoJSON

参考链接：https://www.jianshu.com/p/852d7ad081b3

格式

{
  "type": "Feature",
  "geometry": {
    "type": "Point",
    "coordinates": [125.6, 10.1]
  },
  "properties": {
    "name": "Dinagat Islands"
  }
}

geometry types:Point, LineString,Polygon,MultiPoint,MultiLineString,MultiPolygon.

Future集合使用FeatureCollection对象包含

{
  "type": "FeatureCollection",
  "features": [
        {
　　　　　　"type":"Feature",
          "properties":{},
          "geometry":{
            "type":"Point",
            "coordinates":[105.38085,31.57853]
          }
        }
    ]
}

Point 对应的坐标是一维数组，里面是两个元素，如果是立体的坐标就是三维x,y,z;

[105.38085,31.57853]

MultiPoint

[
        [105.380859375,31.57853542647338],
        [105.580859375,31.52853542647338]
]

 LineString 线要素就是指线段，记录的是线的端点坐标，可视化时会按照记录顺序联结。对于曲线（如贝塞尔曲线）目前还没有很好的表达，但是在地理数据中，曲线一般会用LineString去拟合

[
        [105.60058,30.65681],
        [107.95166,31.98944],
        [109.37988,30.03105],
        [107.79785,29.93589]
]

 MultiLineString

[
        [
               [105.60058,30.65681],
               [107.95166,31.98944],
               [109.37988,30.03105],
               [107.79785,29.93589]
        ],
        [
               [109.37988,30.03105],
               [107.19785,31.23589]
        ]
]

 多边形Polygon 单个多边形是一个3维数组，可以包含多个二维数组，这种情况和MultiPolygon效果很像。

[
    [
      [106.10595,33.33970],
      [106.32568,32.41706],
      [108.03955,32.23138],
      [108.25927,33.15594],
      [106.10595,33.33970]
    ]
]

 多多边形MultiPolygon

   [
        [
            [
                [109.20410,30.088107],
                [115.02685,30.08810],
                [115.02685,32.78727],
                [109.20410,32.78727],
                [109.20410,30.08810]
            ]
        ],
        [
            [
                [112.98339,26.82407],
                [116.69677,26.82407],
                [116.69677,29.03696],
                [112.98339,29.03696],
                [112.98339,26.82407]
            ]
        ]
    ]

 GeometryCollection 是多种基本地理要素的集合，就是里面可以包含点、线、面要素

{
    "type": "GeometryCollection",
    "geometries": [
        {
          "type": "Point",
          "coordinates": [108.62, 31.02819]
        }, {
          "type": "LineString",
          "coordinates": [
　　　　　　　　　　[108.89648,30.10711],
          　　　　[108.218437,30.91717],
          　　　　[109.518437,31.217578]
　　　　　　]
        }
　　]
}

GeometryCollection不需要放在FeatureCollection里

geojson自定义生成工具：http://geojson.io/#map=4/38.89/104.70

datav的中国省市边界下载页：http://datav.aliyun.com/tools/atlas/#&lat=30.37018632615852&lng=106.68898666525287&zoom=3.5

echarts边界下载页：https://hxkj.vip/demo/echartsMap/