使用Newtonsoft.Json反序列化DbGeometry

上面的答案很有效,但是对于SRID(CoordinateSystemId)2193是硬编码的.然而,坐标系统ID可以出现在问题中所示的序列化数据中,或者它可以出现在WellKnownText"SRID = 2193; POINT(0)中0)".此方法也只会读取多边形,但WellKnownText可以是很多东西,如Geometry Collections,Point,Linestring等.要进行检索,可以更新ReadJson方法以使用更通用的FromText方法,如下所示.以上是使用更通用的坐标系更新的类,也适用于任何几何类型.我还添加了地理版本以供参考.

public class DbGeometryConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType.IsAssignableFrom(typeof(string));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject location = JObject.Load(reader);
        JToken token = location["Geometry"]["WellKnownText"];
        string value = token.ToString();
        JToken sridToken = location["Geometry"]["CoordinateSystemId"];
        int srid;
        if (sridToken == null || int.TryParse(sridToken.ToString(), out srid) == false || value.Contains("SRID"))
        {
            //Set default coordinate system here.
            srid = 0;
        }

        DbGeometry converted;
        if (srid > 0)
            converted = DbGeometry.FromText(value, srid);
        else
            converted = DbGeometry.FromText(value);
        return converted;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        // Base serialization is fine
        serializer.Serialize(writer, value);
    }
}

public class DbGeographyConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType.IsAssignableFrom(typeof(string));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject location = JObject.Load(reader);
        JToken token = location["Geometry"]["WellKnownText"];
        string value = token.ToString();
        JToken sridToken = location["Geometry"]["CoordinateSystemId"];
        int srid;
        if (sridToken == null || int.TryParse(sridToken.ToString(), out srid) == false || value.Contains("SRID"))
        {
            //Set default coordinate system here.
            //NOTE: Geography should always have an SRID, and it has to match the data in the database else all comparisons will return NULL!
            srid = 0;
        }
        DbGeography converted;
        if (srid > 0)
            converted = DbGeography.FromText(value, srid);
        else
            converted = DbGeography.FromText(value);
        return converted;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        // Base serialization is fine
        serializer.Serialize(writer, value);
    }
}

System.Data.Spatial.DbGeometry 不能很好地发挥 Newtonsoft.Json

你需要创建一个JsonConverter转换DbGeometry

public class DbGeometryConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return objectType.IsAssignableFrom(typeof(string));
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            JObject location = JObject.Load(reader);
            JToken token = location["Geometry"]["WellKnownText"];
            string value = token.ToString();

            DbGeometry converted = DbGeometry.PolygonFromText(value, 2193);
            return converted;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            // Base serialization is fine
            serializer.Serialize(writer, value);
        }
    }

然后在模型中的属性上添加属性

[JsonConverter(typeof(DbGeometryConverter))]
public DbGeometry Shape { get; set; }

现在当你点击你的BreezeController时,反序列化将由我们新的DbGeometryConverter处理.

希望能帮助到你.