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;
}
}