为什么尽管JsonConverter.ReadJson()确实被调用，但JsonConverter.WriteJson()却从未被调用? [英] Why JsonConverter.WriteJson() never gets called, although JsonConverter.ReadJson() does get called?

问题描述

为什么我的自定义JsonConverter.WriteJson()方法没有被调用?

Why my custom JsonConverter.WriteJson() method doesn't get called ?

class MyType{
    [JsonConverter(typeof(DocumentXamlDeserializer))]
    public string GuiData { get; set; }

    public string SimpleString;
}

尽管ReadJson确实被调用:

public class DocumentXamlDeserializer : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        writer.WriteValue(Gui.Handler.SerializeData());
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var xaml = reader.Value as string;
        Gui.Handler.DeserializeData(xaml);
        return xaml;
    }

    public override bool CanConvert(Type objectType) { return typeof(string).IsAssignableFrom(objectType); }
}

序列化调用:JsonConvert.SerializeObject(dataModel, Formatting.Indented);

反序列化调用:JsonConvert.DeserializeObject<Model>(raw);

推荐答案

显然是因为GuiData为null ...我想我可以指定:

Apparently this is because GuiData is null... I guess I could specify:

TypeNameHandling = TypeNameHandling.Objects

但是我只想序列化GuiData，即使它为空(我在序列化期间设置了它的值)，也没有序列化所有null属性...好吧，如果我找不到更好的方法，我想我会必须满足...

But I want to serialize only GuiData even if it's null (I set its value during serialization), without serializing all null-properties... well, if I don't find better way, I guess I'd have to suffice with it...

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