基于IEnumerable格式化GeoJson<Users>

Question

我有一个基本的API 运行，我可以像往常一样存储数据和获取数据。但是，我在格式化我的内容时遇到问题。我可以使用 HTTPGet 获取所有用户的列表，它看起来像这样...

[
    {
        "userId": "1                           ",
        "geoHash": "123456789",
        "latitude": 1.234,
        "longitude": 5.689,
        "locationDate": "2019-07-01T00:00:00"

    },
    {
        "userId": "2                           ",
        "geoHash": "123456789",
        "latitude": 1.234,
        "longitude": 5.689,
    "locationDate": "2019-07-01T00:00:00"

    },
    {
        "userId": "3                           ",
        "geoHash": "123456789",
        "latitude": 1.234,
        "longitude": 5.689,
    "locationDate": "2019-07-01T00:00:00"

    }
]

但是，我不知道如何将其转换为如下所示的 GeoJson (https://geojson.org/)...

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

这是我获取用户列表的基本方法

        [HttpGet]
        public IEnumerable<Users> GetUsers()
        {
            return _context.Users;
        }

我已经搜索了几个小时，关于这个主题的内容似乎让我有些困惑，我真的很感激这里的一些帮助。

Answer 1

编辑：虽然问题包含用户数据 Json，但评论现在表明它包含在 IEnumerable<Users> 中。下面的代码假定这些值的属性名称与 Json.

中显示的名称相同

您需要 'project' 用户数据作为 GeoJson，最简单的方法是使用匿名类型然后将其序列化：这会根据 [= 创建有效的 GeoJson 13=].

    var users = GetUsers();

    var userGeo = users.Select(u => new
        {
            type = "Feature",
            geometry = new
            {
                type = "Point",
                coordinates = new double[] { u.longitude, u.latitude }
            },
            properties = new {
                name = "User " + u.userId.Trim()
            }
        }
    );

    var featureCollection = new {
        type = "FeatureCollection",
        features = userGeo
    };

    var geoJson = JsonConvert.SerializeObject(featureCollection, Formatting.Indented);

输出：

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [
          5.689,
          1.234
        ]
      },
      "properties": {
        "name": "User 1"
      }
    },
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [
          5.689,
          1.234
        ]
      },
      "properties": {
        "name": "User 2"
      }
    },
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [
          5.689,
          1.234
        ]
      },
      "properties": {
        "name": "User 3"
      }
    }
  ]
}

基于IEnumerable格式化GeoJson<Users>

Format GeoJson based on IEnumerable<Users>

.net

c#

api

ienumerable

geojson