Deserialize json in c # with illegal variable characters

Question

I am writing a .NET library (using Newtonsoft) that interacts with a REST service, and I have a service that returns json, but the json id field is called "$ id". Therefore, I cannot just create the corresponding $ id property in my C # data class. I tried using something like

[JsonObject(MemberSerialization.OptOut)] public class DocData { [JsonProperty("$id")] public string id { get; set; } public string Name { get; set; } } 

but while the name is assigned, the id property does not work. Does anyone know how to map this json key to .NET?

thanks

Answer 1

This seems to be a bug in JSON.NET, and I think you should report it . It works fine in LINQPad for any property name other than $id .

 void Main() { var s = JsonConvert.SerializeObject(new DocData{id = "hi", Name = "world"}).Dump(); JsonConvert.DeserializeObject<DocData>(s).Dump(); } public class DocData { // [JsonProperty("i$d")] // this would work // [JsonProperty("_id")] // as would this // [JsonProperty("$name")] // and even this [JsonProperty("$id")] // but this fails public string id { get; set; } public string Name { get; set; } } 

Obviously, Json.NET uses $id as a reserved word to help deal with object references.

  var dd = new DocData{id = "hi", Name = "world"}; JsonConvert.SerializeObject(new[]{dd, dd}, new JsonSerializerSettings{PreserveReferencesHandling = PreserveReferencesHandling.Objects}).Dump(); // Output: [{"$id":"1","$id":"hi","Name":"world"},{"$ref":"1"}] 

However, it looks like this should allow you to grab the $id property if you are not using link processing.

As a workaround, you can parse it in a JObject and directly output the property:

  var id = JObject.Parse(s)["$id"]; var obj = JsonConvert.DeserializeObject<DocData>(s); obj.id = id;