Custom Json.NET contract resolver for lowercase underscore to CamelCase
asp.net-mvc, c#, json, json.net, rest
Solution
OK, found the solution. I was missing a default constructor for the `Person` class. Once I did that, the mapping worked when calling the `Put` method. In fact, I could also remove the FromBody specifier:
public object Put(int id, Person person)
Problem
I'm working on a REST API in ASP.NET MVC where the resulting serialised JSON uses lowercase_underscore for attributes. From a class `Person` with string properties `FirstName` and `Surname`, I get JSON as follows: ``` { first_name: "Charlie", surname: "Brown" } ``` Note the lowercase_underscore names. The contract resolver I use to do this conversion automatically for me is: ``` public class JsonLowerCaseUnderscoreContractResolver : DefaultContractResolver { private Regex regex = new Regex("(?!(^[A-Z]))([A-Z])"); protected override string ResolvePropertyName(string propertyName) { return regex.Replace(propertyName, "_$2").ToLower(); } } ``` This all works fine, but I don't know how to implement the reverse with Json.NET. So that, for example, I can declare an API method as follows, and it knows to convert incoming JSON in the request body to the appropriate object: ``` public object Put(int id, [FromBody] Person person) ```