MongoDb 将 BsonDocument 集合 转换为强类型 List

var result = new List<User>();
            var collection = MongoHelper.GetDocument(typeof(User).Name);
            var filterBuilder = Builders<BsonDocument>.Filter;
            var filter = filterBuilder.Eq("UserName", "");
            foreach (var d in domainList)
            {
                filter = filter | filterBuilder.Eq("UserName", d);
            }
            var list = MongoHelper.GetList(collection, filter);
            foreach (var m in list)
            {
                var bsElements=m.Elements.Skip(1).Take(m.Elements.Count() - 1).ToList();
                var bsDocs = new BsonDocument();
                for (int i= 0;i < bsElements.Count();i++)
                {
                    bsDocs.SetElement(bsElements[i]);
                }
                string json = bsDocs.ToJson();
                var user = JsonConvert.DeserializeObject<User>(json);
                result.Add(user);
            }
            return result;