Selecting a NamingStrategy when using a JsonConverter on a class property

Question

I've got a c# class that I am trying to correctly serialise using Newtonsoft.Json. The property is an enumeration type and I wish the value to be serialised as the "lowercase version of the enumeration name". There is a JsonConverterAttribute available for specifying this on the property and also a prewritten StringEnumConverter but I need to specify the CamelCaseNamingStrategy on that converter but I can't work out the syntax.

I've tried to assign it on the property itself:

public class C
{
    [JsonConverter(typeof(StringEnumConverter),NamingStrategy=typeof(CamelCaseNamingStrategy))]
    public ChartType ChartType { get; set; }
}

and I've also tried adding it similarly onto the enumeration type itself:

[JsonConverter(typeof(StringEnumConverter),NamingStrategy=typeof(CamelCaseNamingStrategy))]
public enum ChartType { Pie, Bar }

But the syntax is wrong. I can't find any examples of this in the Newtonsoft documentation.

The desired serialision would be: "ChartType":"pie" or "ChartType":"bar"

Any ideas? Thanks.

Substantial

Answer 1

Okay, this appears to work:

[JsonProperty("type")] 
[JsonConverter(typeof(StringEnumConverter), 
     converterParameters:typeof(CamelCaseNamingStrategy))]
public ChartType ChartType { get; }  

As NamingStrategy is a property of the StringEnumConverter it's applied using the converterParameters parameter. This got my desired output. I think an example of this would be useful in Newtonsoft documentation.

Substantial

Answer 2

Another possible solution is using JsonSerializerSettings

var settings = new JsonSerializerSettings
{
    Converters = new List<JsonConverter> {
        new StringEnumConverter(new CamelCaseNamingStrategy())
    }
};
var result = JsonConvert.SerializeObject(obj, settings);

Unclothe

Answer 3

This works for me for enabling camel casing on a single place in a .Net Core web api:

[JsonConverter(typeof(StringEnumConverter), true)]

Note that you can append constructor parameters to the type given by the first parameter and StringEnumConverter has the following overloaded constructor:

StringEnumConverter(bool camelCaseText)

Of course, enabling this globally is normally preferred, as discussed here for example.

Diplodocus

For what it's worth, the boolean camelCaseText parameter used here has been marked obsolete. See newtonsoft.com/json/help/html/… – Pro