Question 110254 in Json Question posted in
Our archive of expertly curated questions and answers provides insights and solutions to common problems related to this popular data interchange format. From parsing and manipulating JSON data to integrating it with various programming languages and web services, our archive has got you covered. Start exploring today and take your JSON skills to the next level

How to fix error: JsonSerializationException: Cannot deserialize the current JSON object

This is what the body looks like:

{
  "_total": 3,
  "users": [
    {
      "username": "person1",
      "points": 3
    },
    {
      "username": "person2",
      "points": 2
    },
    {
      "username": "person3",
      "points": 1
    }
  ]
}

The code:

public class UserData
{
 public string username { get; set; }
 public int points { get; set; }
}

using (var response = await client.SendAsync(request))
 {
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();

  var data = JsonConvert.DeserializeObject<List<UserData>>(body); 
  foreach (UserData userdata in data) 
  {
   Debug.Log(userdata.username + ": " + userdata.points);
  }
 }

The Error:

JsonSerializationException: Cannot deserialize the current JSON object
(e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[UserData]' 
because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.

Tags:

2

Answers


  1. 0

    The class does not match the JSON structure, hence you are getting JsonSerializationException Exception.
    Your model should look something like that:

    public class RootClass
{
    public int _total { get; set; }
    public List<User> users { get; set; }
}

public class User
{
    public string username { get; set; }
    public int points { get; set; }
}

    Than you can do this:

    using (var response = await client.SendAsync(request))
 {
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();

  var data = JsonConvert.DeserializeObject<RootClass>(body); 
  foreach (User userdata in data.users) 
  {
   Debug.Log(userdata.username + ": " + userdata.points);
  }
 }
    Login or Signup to reply.
  2. 0

    you can parse a json string at first and after this to deserialize it to a list of UserData

    var data = JObject.Parse(body)["users"].ToObject<List<UserData>>();
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search