using System;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        var plainString = @"""" + " :riga1" + Environment.NewLine + "ciao \\\\n mamma " + @"""" + " bella :riga2";

        Console.WriteLine("plainString");

        Console.WriteLine(plainString);

        string json = JsonConvert.SerializeObject(plainString);

        Console.WriteLine("");

        Console.WriteLine("json");

        Console.WriteLine(json);

        var deserializedString = JsonConvert.DeserializeObject<string>(json);

        Console.WriteLine("");

        Console.WriteLine("deserializedString");

        Console.WriteLine(deserializedString);

    }

}

​