MongoDB C#驱动程序：枚举上的LINQ筛选将枚举序列化为int

我试图在Mongo数据库中查询一组GeoJSON。文档看起来有点像这样：

{
    "_id" : ObjectId("5db2d9d7a9912b215bb6bfc8"),
    "type" : "Feature",
    "properties" : {
//snip
    },
    "geometry" : {
        "type" : "Polygon",
        "coordinates" : [ //snip ]
}
}

    public class Geometry
    {

        [JsonProperty("type")]
        [BsonElement("type")]
        [BsonRepresentation(BsonType.String)]
        public GeometryType Type { get; set; }
}

Builders<Feature>.Filter.Ne(f => f.Geometry.Type, GeometryType.LineString)

"geometry.type" : {
                "$ne" : 1
            }

BsonSerializer.RegisterSerializer(new EnumSerializer<GeometryType>(BsonType.String));

几何体属性的C#类如下所示：

{
    "_id" : ObjectId("5db2d9d7a9912b215bb6bfc8"),
    "type" : "Feature",
    "properties" : {
//snip
    },
    "geometry" : {
        "type" : "Polygon",
        "coordinates" : [ //snip ]
}
}

    public class Geometry
    {

        [JsonProperty("type")]
        [BsonElement("type")]
        [BsonRepresentation(BsonType.String)]
        public GeometryType Type { get; set; }
}

Builders<Feature>.Filter.Ne(f => f.Geometry.Type, GeometryType.LineString)

"geometry.type" : {
                "$ne" : 1
            }

BsonSerializer.RegisterSerializer(new EnumSerializer<GeometryType>(BsonType.String));

但是我有一些LINQ过滤代码，有点像这样：

{
    "_id" : ObjectId("5db2d9d7a9912b215bb6bfc8"),
    "type" : "Feature",
    "properties" : {
//snip
    },
    "geometry" : {
        "type" : "Polygon",
        "coordinates" : [ //snip ]
}
}

    public class Geometry
    {

        [JsonProperty("type")]
        [BsonElement("type")]
        [BsonRepresentation(BsonType.String)]
        public GeometryType Type { get; set; }
}

Builders<Feature>.Filter.Ne(f => f.Geometry.Type, GeometryType.LineString)

"geometry.type" : {
                "$ne" : 1
            }

BsonSerializer.RegisterSerializer(new EnumSerializer<GeometryType>(BsonType.String));

这不会按预期进行筛选，因为它将LineString序列化为1，而不是数据库中表示它的“LineString”。从字符串反序列化可以很好地工作

---

如何使Mongo驱动程序生成正确的查询？

我必须在启动时为枚举类型注册序列化程序，如下所示：

{
    "_id" : ObjectId("5db2d9d7a9912b215bb6bfc8"),
    "type" : "Feature",
    "properties" : {
//snip
    },
    "geometry" : {
        "type" : "Polygon",
        "coordinates" : [ //snip ]
}
}

    public class Geometry
    {

        [JsonProperty("type")]
        [BsonElement("type")]
        [BsonRepresentation(BsonType.String)]
        public GeometryType Type { get; set; }
}

Builders<Feature>.Filter.Ne(f => f.Geometry.Type, GeometryType.LineString)

"geometry.type" : {
                "$ne" : 1
            }

BsonSerializer.RegisterSerializer(new EnumSerializer<GeometryType>(BsonType.String));

BsonSerializer.RegisterSerializer（新的EnumSerializer（BsonType.String））；