如何从ASP.Net核心中的Json文件播种NetTopologySuite.Geometries.Point数据 [英] How to seed NetTopologySuite.Geometries.Point data from a Json file in ASP.Net core

问题描述

我想从种子文件中为用户对象的位置"数据注入种子

I want to seed "Location" data for my user object from my seed file

其中Point是NetTopologySuite.Geometries.Point的c#对象是我的用户对象的一部分

The c# object, where Point is a NetTopologySuite.Geometries.Point is part of my user object

  public class User: IdentityUser<int> {
      // member data here
      public Point Location { get; set; } // has lat/lng data points
  }

在启动时，我通过执行类似的操作将数据播种到数据库中

I seed data to my db on startup by doing something like this

public void SeedUsers()
{
    if (!_userManager.Users.Any())
    {
        var userData = System.IO.File.ReadAllText("Data/UserSeedData.json");
        var users = JsonConvert.DeserializeObject<List<User>>(userData);

        var roles = new List<Role>
        {
            new Role{Name = "Member"},
            new Role{Name = "Admin"},
            new Role{Name = "Moderator"},
            new Role{Name = "VIP"},
        };

        foreach (var role in roles)
        {
            _roleManager.CreateAsync(role).Wait();
        }

        foreach (var user in users)
        {
            user.Photos.SingleOrDefault().IsApproved = true;
            _userManager.CreateAsync(user, "password").Wait();
            _userManager.AddToRoleAsync(user, "Member").Wait();
        }
     }
 }

具有这样的json数组的json文件"UserSeedData.json"，我希望能够在其中粘贴表示lng/lat数据点的某种位置"数据.

with a json file "UserSeedData.json" of json arrays like this and I want to be able to stick some kind of 'Location' data in there that is representative of lng/lat data points.

{
  "Email": "[e-mail]",
  "Username": "Lola",
  "Gender": "female",
  "DateOfBirth": "1994-02-21",
  "Password": "password",
  "Created": "2017-08-02",
  "LastActive": "2017-08-02",
  "Introduction": "blah blah blah",
  "LookingFor": "blah blah blah",
  "City": "San Francisco",
  "Country": "United States",
  "Longitude": -122.431297,
  "Latitude": 37.773972,
  "Location": // something here!!!
  "Photos": [{
    "url": "https://randomuser.me/api/portraits/women/3.jpg",
    "isMain": true,
    "description": "Non deserunt labore sunt ex laboris et adipisicing ullamco officia minim."
  }]
}

现在，我知道我的种子方法可以做到这一点，但是我正在寻找一种将其包含在.json文件中的方法，以便可以使用不同的数据点

Now I know in my seed method I could do something like this, but I'm looking for a way to include it in my .json file, so I can use different data points

foreach (var user in users)
{
    user.Photos.SingleOrDefault().IsApproved = true;
    user.Location = new Point(-122.4194155, 37.7749295) { SRID = 4326 };
    _userManager.CreateAsync(user, "password").Wait();
    _userManager.AddToRoleAsync(user, "Member").Wait();
}

推荐答案

您可以将NetTopologySuite.Geometries.Point子类化，并添加[JsonConstructor]来解析您的json文件.它应该是其余代码的直接替代.

You could subclass NetTopologySuite.Geometries.Point and add a [JsonConstructor] to parse your json file. It should be a straightforward substitution for the rest of your code.

public class MyPoint : Point
{
    [JsonConstructor]
    public MyPoint(double latitude, double longitude, int srid)
        :base(new GeoAPI.Geometries.Coordinate(longitude, latitude))
    {
        SRID = srid;
    }
}

请注意，纬度= y，经度= x，因此顺序相反.

Note that latitude = y and longitude = x so the order is reversed.

在User类中将MyPoint替换为Point

public class User: IdentityUser<int> {
  // member data here
  public MyPoint Location { get; set; }
}

它应该可以与您的json一起使用.

And it should work with your json as is.

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