MongoDb C# ObjectId序列化问题处理-11

在MongoDB中OjbectId 类型Json序列化反序列化会出错，可以通过以下两种方式解决

1、最简单粗暴的方法，从新定一个一个业务主键比如key,这样的话等于之前的_id不起作用了

2、使用JsonConverter

 public class ObjectIdConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(ObjectId);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            if (reader.TokenType != JsonToken.String)
            {
                throw new Exception(
                    String.Format("Unexpected token parsing ObjectId. Expected String, got {0}.",
                                  reader.TokenType));
            }

            var value = (string)reader.Value;
            return String.IsNullOrEmpty(value) ? ObjectId.Empty : new ObjectId(value);
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            if (value is ObjectId)
            {
                var objectId = (ObjectId)value;

                writer.WriteValue(objectId != ObjectId.Empty ? objectId.ToString() : String.Empty);
            }
            else
            {
                throw new Exception("Expected ObjectId value.");
            }
        }
    }

在ObjectId字段上加一行代码即可

[JsonConverter(typeof(ObjectIdConverter))]
public string _id { get; set; }

3、通过Ignore,一种很有技巧性的写法

[JsonIgnore]
public override  ObjectId _Id { get; set; }

[BsonIgnore]
public string _IdStr
{
     get
     {
          return Id.ToString();
     }
     set
     {
          ObjectId id;
          ObjectId.TryParse(value, out id);
          Id = id;
     }
}

MongoDb C# ObjectId序列化问题处理-11

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