I'm playing a little bit with the new StackOverflow API . Unfortunately, my JSON is a bit weak, so I need some help.
I'm trying to deserialize this JSON of a User:
{"user":{
"user_id": 1,
"user_type": "moderator",
"creation_date": 1217514151,
"display_name": "Jeff Atwood",
...
"accept_rate": 100
}}
into an object which I've decorated with JsonProperty
attributes:
[JsonObject(MemberSerialization.OptIn)]
public class User
{
[JsonProperty("user_id", Required = Required.Always)]
public virtual long UserId { get; set; }
[JsonProperty("display_name", Required = Required.Always)]
public virtual string Name { get; set; }
...
}
I get the following exception:
Newtonsoft.Json.JsonSerializationException: Required property 'user_id' not found in JSON.
Is this because the JSON object is an array? If so, how can I deserialize it to the one User object?
Thanks in advance!
If you don't want to create a wrapper class you can also access the User this way:
String jsonString = "{\"user\":{\"user_id\": 1, \"user_type\": \"moderat...";
JToken root = JObject.Parse(jsonString);
JToken user = root["user"];
User deserializedUser = JsonConvert.DeserializeObject<User>(user.ToString());
See this page in the Json.NET doc for details.
As Alexandre Jasmin said in the comments of your question, the resulting JSON has a wrapper around the actual User
object you're trying to deserialize.
A work-around would be having said wrapper class:
public class UserResults
{
public User user { get; set; }
}
Then the deserialization will work:
using (var sr = new StringReader(json))
using (var jr = new JsonTextReader(sr))
{
var js = new JsonSerializer();
var u = js.Deserialize<UserResults>(jr);
Console.WriteLine(u.user.display_name);
}
There will be future metadata properties on this wrapper, eg response timestamp, so it's not a bad idea to use it!
Similar to @Alexandre Jasmin's answer , you can use an intermediary JsonSerializer to convert instead of the using the high-level JsonConvert
on .ToString()
. No idea if it's any more efficient...
References:
Example:
var root = JObject.Parse(jsonString);
var serializer = new JsonSerializer();
var expectedUserObject = serializer.Deserialize<User>(root["user"].CreateReader());
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