How can I make Newtonsoft accept this property name with an underscore?

Question

I'm retrieving data from an external API. One of their field names is "from_address". So I put that as the JsonPropertyName. But that doesn't work. I've recreated the issue in this fiddle.

public class Program
{
    public class FromAddress
    {
        [JsonPropertyName("name")]
        public string Name { get; set; }

        [JsonPropertyName("email")]
        public string Email { get; set; }
    }

    public class Email
    {
        [JsonPropertyName("id")]
        public string Id { get; set; }

        [JsonPropertyName("from_address")]
        public FromAddress FromAddress { get; set; }
    }

    public static void Main()
    {
        var str = "{\"from_address\":{\"name\":\"me\",\"email\":\"me@me.me\"}, 
\"id\":\"the_one\"}";
        var result = Newtonsoft.Json.JsonConvert.DeserializeObject<Email>(str);
        Console.WriteLine(result.FromAddress != null ? "something" : "nothing"); // nothing
        Console.WriteLine(result.Id); // the_one
        Console.WriteLine(result.FromAddress.Email); // throws a null reference exception
    }
}

I know that the issue is the underscore, because if I replace "from_address" with "fromaddress" in my fiddle (in both the JsonPropertyName and the variable str) it works.

is `JsonPropertyName` from `System.Text.Json`? that's the wrong attribute in that case — Daniel A. White, Jun 13 '22 at 13:19
https://www.newtonsoft.com/json/help/html/jsonpropertyname.htm — Daniel A. White, Jun 13 '22 at 13:21
Then it can be closed as a duplicate of https://stackoverflow.com/questions/15915503/net-newtonsoft-json-deserialize-map-to-a-different-property-name (and I still agree that it is a typo) — gunr2171, Jun 13 '22 at 13:39

score 2 · Accepted Answer · answered Jun 13 '22 at 13:23

2

JsonPropertyName is from System.Text.Json so won't work correctly with Newtonsoft.

Try using the equivalent Newtonsoft attribute JsonProperty.

e.g.:

[JsonProperty("from_address")]
public FromAddress FromAddress { get; set; }

answered Jun 13 '22 at 13:23

YungDeiza

3,128
1
7
32

How can I make Newtonsoft accept this property name with an underscore?

1 Answers1