我将 DbGeography 多边形存储在数据库中。我的控制器从数据库中获取多边形，我需要将它们转换为 JSON。
var polygons = db.Areas
.Where(x => x.Type == type)
.Select(x => new ViewArea
{
Id = x.Id,
Type = x.Type,
Rate = x.Rate,
Polygon = x.Polygon,
});
return Json(polygons, JsonRequestBehavior.AllowGet);
我尝试使用 getJSON 从服务器获取多边形，但无法将 DbGeography 转换为 JSON。怎么做，那个转换？
首先，您可能不想要任何旧的 JSON，因为有一个标准GeoJSON。
您可以在 DbGeography 上使用如下所示的 NewtonSoft JsonConverter 属性：
public class Foo
{
[JsonConverter(typeof(DbGeographyGeoJsonConverter))]
public DbGeography Polygon { get; set; }
}
您可以将 Foo 的实例转换为 JSON，例如：
var foo = new Foo { Polygon = DbGeography.FromText(
"Polygon((22.3 77.4, 22.5 77.5, 22.7 77.5, 22.3 77.4))") };
var jsonText = JsonConvert.SerializeObject(foo);
这应该给你类似的东西：
{“多边形”：{“类型”：“多边形”，“坐标”：[[[22.3,77.4],[22.5,77.5],[22.7,77.5],[22.3,77.4]]]}}
现在，DbGeographyGeoJsonConverter 类有点复杂，我在下面提供的那个并不完整（这里有一个更完整的版本）。使用它生成的任何 JSON 就足够了。部分复杂性来自于它是从我用来处理地理空间知名二进制和知名文本的其他类中部分复制粘贴而来的。
using System;
using System.Collections.Generic;
using System.Data.Entity.Spatial;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using AplPed.Common;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
/// <summary>
/// The <see cref="DbGeography"/> GeoJSON converter
/// </summary>
public class DbGeographyGeoJsonConverter : JsonConverter
{
/// <summary>
/// Well-known-binary point value.
/// </summary>
private const int PointWkb = 1;
/// <summary>
/// Well-known-binary line value.
/// </summary>
private const int LineStringWkb = 2;
/// <summary>
/// Well-known-binary polygon value.
/// </summary>
private const int PolygonWkb = 3;
/// <summary>
/// Well-known-binary multi-point value.
/// </summary>
private const int MultiPointWkb = 4;
/// <summary>
/// Well-known-binary multi-line value.
/// </summary>
private const int MultiLineStringWkb = 5;
/// <summary>
/// Well-known-binary multi-polygon value.
/// </summary>
private const int MultiPolygonWkb = 6;
/// <summary>
/// Well-known-binary geometry collection value.
/// </summary>
private const int GeometryCollectionWkb = 7;
/// <summary>
/// Well-known-binary line value.
/// </summary>
private static readonly Dictionary<int, string> WkbTypes =
new Dictionary<int, string>
{
{ PointWkb, "Point" },
{ LineStringWkb, "LineString" },
{ PolygonWkb, "Polygon" },
{ MultiPointWkb, "MultiPoint" },
{ MultiLineStringWkb, "MultiLineString" },
{ MultiPolygonWkb, "MultiPolygon" },
{ GeometryCollectionWkb, "GeometryCollection" }
};
/// <summary>
/// The types derived from <see cref="GeoBase"/> accessed by name.
/// </summary>
private static readonly Dictionary<string, Type> GeoBases =
new Dictionary<string, Type>
{
{ "Point", typeof(Point) },
{ "LineString", typeof(LineString) },
{ "Polygon", typeof(Polygon) },
{ "MultiPoint", typeof(MultiPoint) },
{ "MultiLineString", typeof(MultiLineString) },
{ "MultiPolygon", typeof(MultiPolygon) },
{ "GeometryCollection", typeof(Collection) },
};
/// <summary>
/// Read the GeoJSON type value.
/// </summary>
/// <param name="jsonObject">
/// The JSON object.
/// </param>
/// <param name="coordinateSystem">
/// The coordinate System.
/// </param>
/// <returns>
/// A function that can read the value.
/// </returns>
/// <exception cref="ArgumentException">
/// Unexpected JSON.
/// </exception>
/// <remarks>
/// Leaves the reader positioned where the value should start.
/// </remarks>
public static GeoBase ParseJsonObjectToGeoBase(JObject jsonObject, out int? coordinateSystem)
{
var type = jsonObject["type"];
if (type == null)
{
throw new ArgumentException(string.Format("Expected a \"type\" property, found [{0}]", string.Join(", ", jsonObject.Properties().Select(p => p.Name))));
}
if (type.Type != JTokenType.String)
{
throw new ArgumentException(string.Format("Expected a string token for the type of the GeoJSON type, got {0}", type.Type), "jsonObject");
}
Type geoType;
if (!GeoBases.TryGetValue(type.Value<string>(), out geoType))
{
throw new ArgumentException(
string.Format(
"Got unsupported GeoJSON object type {0}. Expected one of [{1}]",
type.Value<string>(),
string.Join(", ", GeoBases.Keys)),
"jsonObject");
}
var geoObject = geoType == typeof(Collection) ? jsonObject["geometries"] : jsonObject["coordinates"];
if (geoObject == null)
{
throw new ArgumentException(
string.Format(
"Expected a field named \"{0}\", found [{1}]",
geoType == typeof(Collection) ? "geometries" : "coordinates",
string.Join(", ", jsonObject.Properties().Select(p => p.Name))),
"jsonObject");
}
var crs = jsonObject["crs"];
coordinateSystem = crs != null ? ParseCrs(crs.Value<JObject>()) : null;
var geo = (GeoBase)Activator.CreateInstance(geoType);
geo.ParseJson(geoObject.Value<JArray>());
return geo;
}
/// <inheritdoc/>
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
BinaryReader lebr;
BinaryReader bebr;
var geographyValue = value as DbGeography;
int coordinateSystemId;
if (geographyValue != null)
{
var br = new BinaryReader(new MemoryStream(geographyValue.AsBinary()));
lebr = BitConverter.IsLittleEndian ? br : new ReverseEndianBinaryReader(br.BaseStream);
bebr = BitConverter.IsLittleEndian ? new ReverseEndianBinaryReader(br.BaseStream) : br;
coordinateSystemId = geographyValue.CoordinateSystemId;
}
else
{
var geometryValue = value as DbGeometry;
if (geometryValue != null)
{
var br = new BinaryReader(new MemoryStream(geometryValue.AsBinary()));
lebr = BitConverter.IsLittleEndian ? br : new ReverseEndianBinaryReader(br.BaseStream);
bebr = BitConverter.IsLittleEndian ? new ReverseEndianBinaryReader(br.BaseStream) : br;
coordinateSystemId = geometryValue.CoordinateSystemId;
}
else
{
throw new ArgumentException(
string.Format("Expecting DbGeography or DbGeometry, got {0}", value.GetType().CSharpName()), "value");
}
}
var jsonObject = WriteObject(lebr, bebr);
jsonObject.Add(
"crs",
new JObject
{
new JProperty("type", "name"),
new JProperty(
"properties",
new JObject { new JProperty("name", string.Format("EPSG:{0}", coordinateSystemId)) })
});
writer.WriteRawValue(jsonObject.ToString(Formatting.None));
}
/// <inheritdoc/>
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
// Load JObject from stream
JObject jsonObject = JObject.Load(reader);
// Create target object based on JObject
object target = CreateDbGeo(jsonObject, objectType);
// Populate the object properties
serializer.Populate(jsonObject.CreateReader(), target);
return target;
}
/// <inheritdoc/>
public override bool CanConvert(Type objectType)
{
return objectType == typeof(DbGeography) || objectType == typeof(DbGeometry);
}
/// <summary>
/// Parse the coordinate system object and return it's value.
/// </summary>
/// <param name="jsonObject">
/// The JSON object.
/// </param>
/// <returns>
/// The coordinate system value; null if couldn't parse it (only a couple EPSG-style values).
/// </returns>
private static int? ParseCrs(JObject jsonObject)
{
var properties = jsonObject["properties"];
if (properties != null && properties.Type == JTokenType.Object)
{
var p = properties.Value<JObject>();
var name = p["name"];
if (name != null)
{
var s = name.Value<string>();
if (!string.IsNullOrWhiteSpace(s))
{
var m = Regex.Match(
s,
@"^\s*(urn\s*:\s*ogc\s*:\s*def\s*:crs\s*:EPSG\s*:\s*[\d.]*\s*:|EPSG\s*:)\s*(?<value>\d+)\s*$",
RegexOptions.ExplicitCapture | RegexOptions.IgnoreCase);
if (m.Success)
{
return int.Parse(m.Groups["value"].Value);
}
}
}
}
return null;
}
/// <summary>
/// Get well known binary from a <see cref="JsonReader"/>.
/// </summary>
/// <param name="jsonObject">
/// The JSON object.
/// </param>
/// <param name="defaultCoordinateSystemId">
/// The default coordinate system id.
/// </param>
/// <returns>
/// A tuple of the well-known-binary and the coordinate system identifier.
/// </returns>
/// <exception cref="ArgumentException">
/// Unexpected JSON.
/// </exception>
private static Tuple<byte[], int> GetWellKnownBinary(JObject jsonObject, int defaultCoordinateSystemId)
{
var ob = new MemoryStream();
int? coordinateSystemId;
var geoBase = ParseJsonObjectToGeoBase(jsonObject, out coordinateSystemId);
geoBase.WellKnownBinary(ob);
return new Tuple<byte[], int>(ob.ToArray(), coordinateSystemId.HasValue ? coordinateSystemId.Value : defaultCoordinateSystemId);
}
/// <summary>
/// Write a well-known binary object to JSON.
/// </summary>
/// <param name="lebr">
/// The little-endian binary reader.
/// </param>
/// <param name="bebr">
/// The big-endian binary reader.
/// </param>
/// <exception cref="ArgumentException">
/// Unexpected well-known binary.
/// </exception>
/// <returns>
/// The <see cref="JObject"/> for the given binary data.
/// </returns>
private static JObject WriteObject(BinaryReader lebr, BinaryReader bebr)
{
var jsonObject = new JObject();
var br = lebr.ReadByte() == 0 ? bebr : lebr;
int gtype = br.ReadInt32();
string objTypeName;
if (!WkbTypes.TryGetValue(gtype, out objTypeName))
{
throw new ArgumentException(
string.Format(
"Unsupported type {0}. Supported types: {1}",
gtype,
string.Join(", ", WkbTypes.Select(kv => string.Format("({0}, {1}", kv.Key, kv.Value)))));
}
jsonObject.Add("type", objTypeName);
if (gtype == GeometryCollectionWkb)
{
var array = new JArray();
int count = br.ReadInt32();
for (int i = 0; i < count; ++i)
{
array.Add(WriteObject(lebr, bebr));
}
jsonObject.Add("geometries", array);
}
else
{
var array = new JArray();
switch (gtype)
{
case PointWkb:
array.Add(br.ReadDouble());
array.Add(br.ReadDouble());
break;
case LineStringWkb:
foreach (var a in WriteLine(br))
{
array.Add(a);
}
break;
case PolygonWkb:
foreach (var a in WritePolygon(br))
{
array.Add(a);
}
break;
case MultiPointWkb:
int pointCount = br.ReadInt32();
for (int i = 0; i < pointCount; ++i)
{
br = lebr.ReadByte() == 0 ? bebr : lebr;
gtype = br.ReadInt32();
if (gtype != PointWkb)
{
throw new ArgumentException(
string.Format("Expected a type of 1, got {0}", gtype),
"lebr");
}
array.Add(new JArray { br.ReadDouble(), br.ReadDouble() });
}
break;
case MultiLineStringWkb:
int lineCount = br.ReadInt32();
for (int i = 0; i < lineCount; ++i)
{
br = lebr.ReadByte() == 0 ? bebr : lebr;
gtype = br.ReadInt32();
if (gtype != LineStringWkb)
{
throw new ArgumentException(
string.Format("Expected a type of 2, got {0}", gtype),
"lebr");
}
var lineArray = new JArray();
foreach (var a in WriteLine(br))
{
lineArray.Add(a);
}
array.Add(lineArray);
}
break;
case MultiPolygonWkb:
int polygonCount = br.ReadInt32();
for (int i = 0; i < polygonCount; ++i)
{
br = lebr.ReadByte() == 0 ? bebr : lebr;
gtype = br.ReadInt32();
if (gtype != PolygonWkb)
{
throw new ArgumentException(
string.Format("Expected a type of 3, got {0}", gtype),
"lebr");
}
var polygonArray = new JArray();
foreach (var a in WritePolygon(br))
{
polygonArray.Add(a);
}
array.Add(polygonArray);
}
break;
default:
throw new ArgumentException(string.Format("Unsupported geo-type {0}", gtype), "lebr");
}
jsonObject.Add("coordinates", array);
}
return jsonObject;
}
/// <summary>
/// Write a JSON polygon from well-known binary.
/// </summary>
/// <param name="br">
/// Read from this.
/// </param>
/// <returns>
/// The <see cref="JArray"/> enumerable for the polygon.
/// </returns>
private static IEnumerable<JArray> WritePolygon(BinaryReader br)
{
var ret = new List<JArray>();
int ringCount = br.ReadInt32();
for (int ri = 0; ri < ringCount; ++ri)
{
var array = new JArray();
foreach (var a in WriteLine(br))
{
array.Add(a);
}
ret.Add(array);
}
return ret;
}
/// <summary>
/// Write a JSON line from well-known binary.
/// </summary>
/// <param name="br">
/// Read from this.
/// </param>
/// <returns>
/// The <see cref="JArray"/> enumerable for the line.
/// </returns>
private static IEnumerable<JArray> WriteLine(BinaryReader br)
{
var ret = new List<JArray>();
int count = br.ReadInt32() * 2;
for (int i = 0; i < count; i += 2)
{
var array = new JArray { br.ReadDouble(), br.ReadDouble() };
ret.Add(array);
}
return ret;
}
/// <summary>
/// Create a <see cref="DbGeography"/> or <see cref="DbGeometry"/> from <paramref name="jsonObject"/>.
/// </summary>
/// <param name="jsonObject">
/// The JSON object.
/// </param>
/// <param name="objectType">
/// The object type.
/// </param>
/// <returns>
/// The <see cref="DbGeography"/> or <see cref="DbGeometry"/>
/// </returns>
/// <exception cref="ArgumentException">
/// <paramref name="objectType"/> is not a <see cref="DbGeography"/> or <see cref="DbGeometry"/>.
/// </exception>
private static object CreateDbGeo(JObject jsonObject, Type objectType)
{
Func<Tuple<byte[], int>, object> returnValue;
int defaultCoordinateSystemId;
if (typeof(DbGeography).IsAssignableFrom(objectType))
{
returnValue = x => (object)DbGeography.FromBinary(x.Item1, x.Item2);
defaultCoordinateSystemId = DbGeography.DefaultCoordinateSystemId;
}
else if (typeof(DbGeometry).IsAssignableFrom(objectType))
{
returnValue = x => (object)DbGeometry.FromBinary(x.Item1, x.Item2);
defaultCoordinateSystemId = DbGeometry.DefaultCoordinateSystemId;
}
else
{
throw new ArgumentException(string.Format("Expected a DbGeography or DbGeometry objectType. Got {0}", objectType.CSharpName()), "objectType");
}
return jsonObject.Type == JTokenType.Null || jsonObject.Type == JTokenType.None ? null : returnValue(GetWellKnownBinary(jsonObject, defaultCoordinateSystemId));
}
/// <summary>
/// A <see cref="BinaryReader"/> that expects byte-reversed numeric values.
/// </summary>
public class ReverseEndianBinaryReader : BinaryReader
{
/// <summary>
/// Initializes a new instance of the <see cref="ReverseEndianBinaryReader"/> class.
/// </summary>
/// <param name="stream">
/// The stream.
/// </param>
public ReverseEndianBinaryReader(Stream stream)
: base(stream)
{
}
/// <inheritdoc/>
public override short ReadInt16()
{
return BitConverter.ToInt16(this.ReadBytes(2).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override int ReadInt32()
{
return BitConverter.ToInt32(this.ReadBytes(4).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override long ReadInt64()
{
return BitConverter.ToInt64(this.ReadBytes(8).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override ushort ReadUInt16()
{
return BitConverter.ToUInt16(this.ReadBytes(2).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override uint ReadUInt32()
{
return BitConverter.ToUInt32(this.ReadBytes(4).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override ulong ReadUInt64()
{
return BitConverter.ToUInt64(this.ReadBytes(8).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override float ReadSingle()
{
return BitConverter.ToSingle(this.ReadBytes(4).Reverse().ToArray(), 0);
}
/// <inheritdoc/>
public override double ReadDouble()
{
return BitConverter.ToDouble(this.ReadBytes(8).Reverse().ToArray(), 0);
}
}
/// <summary>
/// Base class for the types that know how to parse JSON and write well-known binary.
/// </summary>
public abstract class GeoBase
{
/// <summary>
/// The point well-known bytes descriptor.
/// </summary>
protected static readonly byte[] PointWkbs = BitConverter.GetBytes(PointWkb);
/// <summary>
/// The line-string well-known bytes descriptor.
/// </summary>
protected static readonly byte[] LineStringWkbs = BitConverter.GetBytes(LineStringWkb);
/// <summary>
/// The polygon well-known bytes descriptor.
/// </summary>
protected static readonly byte[] PolygonWkbs = BitConverter.GetBytes(PolygonWkb);
/// <summary>
/// The multi-point well-known bytes descriptor.
/// </summary>
protected static readonly byte[] MultiPointWkbs = BitConverter.GetBytes(MultiPointWkb);
/// <summary>
/// The multi-line-string well-known bytes descriptor.
/// </summary>
protected static readonly byte[] MultiLineStringWkbs = BitConverter.GetBytes(MultiLineStringWkb);
/// <summary>
/// The multi-polygon well-known bytes descriptor.
/// </summary>
protected static readonly byte[] MultiPolygonWkbs = BitConverter.GetBytes(MultiPolygonWkb);
/// <summary>
/// The collection well-known bytes descriptor.
/// </summary>
protected static readonly byte[] GeometryCollectionWkbs = BitConverter.GetBytes(GeometryCollectionWkb);
/// <summary>
/// Helper function to parse a <see cref="List{T}"/> of <see cref="Position"/>.
/// </summary>
/// <param name="array">
/// Get JSON from this.
/// </param>
/// <returns>
/// The parsed JSON.
/// </returns>
/// <exception cref="ArgumentException">
/// Unexpected JSON.
/// </exception>
public static List<Position> ParseListPosition(JArray array)
{
if (array.Cast<JArray>().Any(l => l.Count < 2))
{
throw new ArgumentException(
string.Format(
"Expected all points to have greater than two points, got {0} with zero and {1} with one",
array.Cast<JArray>().Count(l => l.Count == 0),
array.Cast<JArray>().Count(l => l.Count == 1)),
"array");
}
return array.Select(l => new Position { P1 = (double)l[0], P2 = (double)l[1] }).ToList();
}
/// <summary>
/// Helper function to parse a <see cref="List{T}"/> of <see cref="List{T}"/> of <see cref="Position"/>.
/// </summary>
/// <param name="array">
/// Get JSON from this.
/// </param>
/// <returns>
/// The parsed JSON.
/// </returns>
/// <exception cref="ArgumentException">
/// Unexpected JSON.
/// </exception>
public static List<List<Position>> ParseListListPosition(JArray array)
{
if (array.Cast<JArray>().Any(r => r.Cast<JArray>().Any(l => l.Count < 2)))
{
throw new ArgumentException(
string.Format(
"Expected all points to have greater than two points, got {0} with zero and {1} with one",
array.Cast<JArray>().Sum(r => r.Cast<JArray>().Count(l => l.Count == 0)),
array.Cast<JArray>().Sum(r => r.Cast<JArray>().Count(l => l.Count == 1))),
"array");
}
return array.Select(r => r.Select(l => new Position { P1 = (double)l[0], P2 = (double)l[1] }).ToList()).ToList();
}
/// <summary>
/// Helper function to parse a <see cref="List{T}"/> of <see cref="List{T}"/> of <see cref="List{T}"/> of <see cref="Position"/>.
/// </summary>
/// <param name="array">
/// Get JSON from this.
/// </param>
/// <returns>
/// The parsed JSON.
/// </returns>
/// <exception cref="ArgumentException">
/// Unexpected JSON.
/// </exception>
public static List<List<List<Position>>> ParseListListListPosition(JArray array)
{
if (array.Cast<JArray>().Any(p => p.Cast<JArray>().Any(r => r.Cast<JArray>().Any(l => l.Count < 2))))
{
throw new ArgumentException(
string.Format(
"Expected all points to have greater than two points, got {0} with zero and {1} with one",
array.Cast<JArray>().Sum(p => p.Cast<JArray>().Sum(r => r.Cast<JArray>().Count(l => l.Count == 0))),
array.Cast<JArray>().Sum(p => p.Cast<JArray>().Sum(r => r.Cast<JArray>().Count(l => l.Count == 1)))),
"array");
}
return array.Select(p => p.Select(r => r.Select(l => new Position { P1 = (double)l[0], P2 = (double)l[1] }).ToList()).ToList()).ToList();
}
/// <summary>
/// Write the contents to <paramref name="sout"/> in well-known
/// binary format.
/// </summary>
/// <param name="sout">
/// The stream to write the position to.
/// </param>
public abstract void WellKnownBinary(Stream sout);
/// <summary>
/// Parse JSON into the <see cref="GeoBase"/>-derived type.
/// </summary>
/// <param name="array">
/// Get JSON from this.
/// </param>
public abstract void ParseJson(JArray array);
}
/// <summary>
/// The position.
/// </summary>
public class Position : GeoBase
{
/// <summary>
/// Gets or sets the first value of the position.
/// </summary>
public double P1 { get; set; }
/// <summary>
/// Gets or sets the second value of the position.
/// </summary>
public double P2 { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
sout.Write(BitConverter.GetBytes(this.P1), 0, 8);
sout.Write(BitConverter.GetBytes(this.P2), 0, 8);
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
if (array.Count < 2)
{
throw new ArgumentException(string.Format("Expected at least 2 points for a position, got {0}", array.Count), "array");
}
this.P1 = (double)array[0];
this.P2 = (double)array[1];
}
}
// ReSharper disable RedundantNameQualifier
/// <summary>
/// The point.
/// </summary>
public class Point : GeoBase
{
/// <summary>
/// Gets or sets the position.
/// </summary>
public Position Position { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
sout.WriteByte(BitConverter.IsLittleEndian ? (byte)1 : (byte)0);
sout.Write(GeoBase.PointWkbs, 0, 4);
this.Position.WellKnownBinary(sout);
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.Position = new Position();
this.Position.ParseJson(array);
}
}
/// <summary>
/// The line string.
/// </summary>
public class LineString : GeoBase
{
/// <summary>
/// Gets or sets the points.
/// </summary>
public List<Point> Points { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
sout.WriteByte(BitConverter.IsLittleEndian ? (byte)1 : (byte)0);
sout.Write(GeoBase.LineStringWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(this.Points.Count), 0, 4);
foreach (var point in this.Points)
{
point.Position.WellKnownBinary(sout);
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
if (array.Cast<JArray>().Any(l => l.Count < 2))
{
throw new ArgumentException(
string.Format(
"Expected all points to have greater than two points, got {0} with zero and {1} with one",
array.Cast<JArray>().Count(l => l.Count == 0),
array.Cast<JArray>().Count(l => l.Count == 1)),
"array");
}
this.Points = array.Cast<JArray>().Select(l => new Point { Position = new Position { P1 = (double)l[0], P2 = (double)l[1] } }).ToList();
}
}
/// <summary>
/// The polygon.
/// </summary>
public class Polygon : GeoBase
{
/// <summary>
/// Gets or sets the rings.
/// </summary>
public List<List<Position>> Rings { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
sout.WriteByte(BitConverter.IsLittleEndian ? (byte)1 : (byte)0);
sout.Write(GeoBase.PolygonWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(this.Rings.Count), 0, 4);
foreach (var ring in this.Rings)
{
sout.Write(BitConverter.GetBytes(ring.Count), 0, 4);
foreach (var position in ring)
{
position.WellKnownBinary(sout);
}
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.Rings = GeoBase.ParseListListPosition(array);
}
}
/// <summary>
/// The multi-point.
/// </summary>
public class MultiPoint : GeoBase
{
/// <summary>
/// Gets or sets the points.
/// </summary>
public List<Position> Points { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
byte order = BitConverter.IsLittleEndian ? (byte)1 : (byte)0;
sout.WriteByte(order);
sout.Write(GeoBase.MultiPointWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(this.Points.Count), 0, 4);
foreach (var point in this.Points)
{
sout.WriteByte(order);
sout.Write(GeoBase.PointWkbs, 0, 4); // Point
point.WellKnownBinary(sout);
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.Points = GeoBase.ParseListPosition(array);
}
}
/// <summary>
/// The multi-line.
/// </summary>
public class MultiLineString : GeoBase
{
/// <summary>
/// Gets or sets the line strings.
/// </summary>
public List<List<Position>> LineStrings { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
byte order = BitConverter.IsLittleEndian ? (byte)1 : (byte)0;
sout.WriteByte(order);
// ReSharper disable once RedundantNameQualifier
sout.Write(GeoBase.MultiLineStringWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(this.LineStrings.Count), 0, 4);
foreach (var lineString in this.LineStrings)
{
sout.WriteByte(order);
sout.Write(GeoBase.LineStringWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(lineString.Count), 0, 4);
foreach (var position in lineString)
{
position.WellKnownBinary(sout);
}
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.LineStrings = GeoBase.ParseListListPosition(array);
}
}
/// <summary>
/// The multi-polygon.
/// </summary>
public class MultiPolygon : GeoBase
{
/// <summary>
/// Gets or sets the polygons.
/// </summary>
public List<List<List<Position>>> Polygons { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream sout)
{
byte order = BitConverter.IsLittleEndian ? (byte)1 : (byte)0;
sout.WriteByte(order);
sout.Write(GeoBase.MultiPolygonWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(this.Polygons.Count), 0, 4);
foreach (var polygon in this.Polygons)
{
sout.WriteByte(order);
sout.Write(GeoBase.PolygonWkbs, 0, 4);
sout.Write(BitConverter.GetBytes(polygon.Count), 0, 4);
foreach (var ring in polygon)
{
sout.Write(BitConverter.GetBytes(ring.Count), 0, 4);
foreach (var position in ring)
{
position.WellKnownBinary(sout);
}
}
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.Polygons = GeoBase.ParseListListListPosition(array);
}
}
/// <summary>
/// The <see cref="GeoBase"/> collection.
/// </summary>
public class Collection : GeoBase
{
/// <summary>
/// Gets or sets the entries.
/// </summary>
public List<GeoBase> Entries { get; set; }
/// <inheritdoc/>
public override void WellKnownBinary(Stream o)
{
o.WriteByte(BitConverter.IsLittleEndian ? (byte)1 : (byte)0);
o.Write(GeoBase.GeometryCollectionWkbs, 0, 4);
o.Write(BitConverter.GetBytes(this.Entries.Count), 0, 4);
foreach (var entry in this.Entries)
{
entry.WellKnownBinary(o);
}
}
/// <inheritdoc/>
public override void ParseJson(JArray array)
{
this.Entries = new List<GeoBase>();
foreach (var elem in array)
{
if (elem.Type != JTokenType.Object)
{
throw new ArgumentException(
string.Format("Expected object elements of the collection array, got {0}", elem.Type),
"array");
}
int? dummyCoordinateSystem;
this.Entries.Add(DbGeographyGeoJsonConverter.ParseJsonObjectToGeoBase((JObject)elem, out dummyCoordinateSystem));
}
}
}
// ReSharper restore RedundantNameQualifier
}
我刚刚实现了@mheyman 所指的完整版本。@DiomedesDomínguez 已经在评论中发布了一个新链接，因为原来的链接已经死了，但我也会在这里添加它。
如果你Newtonsoft.Json已经安装了，你需要做两件事来让它工作。首先是下载nugetMicrosoft.SqlServer.Types
https://www.nuget.org/packages/Microsoft.SqlServer.Types/
要将使用空间数据类型的应用程序部署到未安装“SQL Server 的系统 CLR 类型”的计算机，您还需要部署本机程序集 SqlServerSpatial140.dll。此程序集的 x86（32 位）和 x64（64 位）版本都已添加到您的项目中的 SqlServerTypes\x86 和 SqlServerTypes\x64 子目录下。如果未安装 C++ 运行时，还包括本机程序集 msvcr120.dll。
如果您正在运行 Web 应用程序，请将其添加到Global.asax->Application_Start()并添加以下行：
SqlServerTypes.Utilities.LoadNativeAssemblies(Server.MapPath("~/bin"));;
如果您有桌面应用程序，请在使用任何空间数据类型之前使用此行：
SqlServerTypes.Utilities.LoadNativeAssemblies(AppDomain.CurrentDomain.BaseDirectory);
现在除了调用CSharpName()for的方法外，一切都解决了Type。在示例中是这样使用的：value.GetType().CSharpName(). 即使仅用于异常处理，我仍然喜欢使用完整的示例。
搜索方法我发现了以下线程：
https://stackoverflow.com/a/17376472/3850405
public static string CSharpName(this Type type)
{
var sb = new StringBuilder();
var name = type.Name;
if (!type.IsGenericType) return name;
sb.Append(name.Substring(0, name.IndexOf('`')));
sb.Append("<");
sb.Append(string.Join(", ", type.GetGenericArguments()
.Select(t => t.CSharpName())));
sb.Append(">");
return sb.ToString();
}
当我添加这个时，我可以使用该应用程序。
您还可以查看以下项目以获取更多示例：
https://github.com/MannusEtten/GeoJson/tree/master/GeoJsonLibrary
我也最终需要反过来，可以这样做：
DbGeography dbGeography = JsonConvert.DeserializeObject<DbGeography>(geoJson, new DbGeographyGeoJsonConverter());