How to ignore data in JSON.NET that changes between returns

问题

I'm parsing JSON data return by a third party.

I have my class generated with JSON2CSharp which works for the first sample we received. I tweaked it to have some JsonProperty settings so that it doesn't require certain properties that are not always present.

Now I received more samples and one of the datablobs changed format

from needing

public Translations Translations { get; set; }

public List<Translations> Translations { get; set; }

The blob however is information we do not need, for both performance and not having to deal with that and other pieces of information we do not need changing format, it would be ideal to just ignore it when deserializing it.

Now the real question is, should "JsonIgnore" just ignore the entire blob of data irregardless if it is in a different format then defined in the class? Or do I have to program around that?

So if I do

[JsonIgnore]
public string Translations { get; set; }

will it also ignore Translations when it gets sent a list or an object?

Can I use the same syntax with JsonIgnore as I can with JsonProperty and just say

[JsonIgnore(PropertyName = "translations")]

or does JsonIgnore just toss out anything it receives?

Additionally question:

Is it convention that when there are no translations, I get:

"translations":[]

and when there are translations I get:

"translations":{"CA":"blabla","DD":"C : blablah"}

Or is this likely a bug in the third party's website?

ADDED:

1: The Translations can switch between string, list and object between every fetch of the JSON.

2: For using DataMembers ignoring everything I don't actually need, in a class with subclasses, do I have to tell it that the subclass is [DataMember] or the subclasses properties are [DataMember]?

回答1:

I would explicitly specify exactly the properties I wanted serialized/deserialized in my data class using DataContractAttribute and DataMemberAttributes for the members you actually want to deserialize.

This is opt in, so no attempt is made to shoehorn anything extra in your JSON into your data class, and anything extra in your data class doesn't show up in serialized JSON.

So assuming your class right now looks like this:

class MyData {
    // Old member
    // public Translations Translations { get; set; }

    public List<Translation> Translations { get; set; }

    public string ThisShouldBeSerialized { get; set; }
}

You can change it so things that you want serialized are explicitly marked as such, and anything not marked for serialization is ignored by default:

[DataContract]
class MyData {
    // Old member
    // public Translations Translations { get; set; }

    public List<Translation> Translations { get; set; }

    [DataMember]
    public string ThisShouldBeSerialized { get; set; }
}

And then:

var myJSON = @"{ 
    'ThisShouldBeSerialized': 'test', 
    'Translations': { 
         'Some' : 'Strange', 
         'Data' : 'Blob' 
     }
}";

var result = JsonConvert.DeserializeObject<MyData>(myJSON);

来源：https://stackoverflow.com/questions/28434914/how-to-ignore-data-in-json-net-that-changes-between-returns

标签

json

deserialization