JsonConverter
JsonConverter is an abstraction used by JSON serialization frameworks to customize how a specific type is serialized to JSON and deserialized from JSON. Implementations define the rules for writing a value to JSON and reading JSON back into an object, enabling support for non-standard representations, custom formats, or polymorphic types.
In the Newtonsoft.Json library, JsonConverter is a class you derive from and implement CanConvert(Type), WriteJson(JsonWriter, object,
In System.Text.Json, the modern .NET library, there is a generic JsonConverter<T> (and a non-generic JsonConverter for
Common use cases include representing dates in a specific format, serializing enums as strings, handling polymorphic
Best practices include keeping converters focused and fast, avoiding re-entrancy issues, carefully handling nulls, and testing