Question

I’m parsing a JSON string into an ObservableCollection, but when I do it Json.net throws this error:

Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON array (e.g. [1,2,3]) into type ‘MVPTracker.ViewModels.DataModels+League+Position’ because the type requires a JSON object (e.g. {“name”:”value”}) to deserialize correctly.
To fix this error either change the JSON to a JSON object (e.g. {“name”:”value”}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array.

My DataModel, ViewModel and Loading are below:

DataModel:

public class League
    {
        public string name { get; set; }
        public string code { get; set; }
        public string imageUrl { get; set; }
        public Position positions = new Position();

        public class Position
        {
            public string name { get; set; }
            public string code { get; set; }
            public string imageUrl { get; set; }
            public string[] statistics { get; set; }
        }
    }

Loading/ViewModel:

private ObservableCollection<DataModels.League> _leagues = new ObservableCollection<DataModels.League>();
    public ObservableCollection<DataModels.League> Leagues
    {
        get { return _leagues; }
        set { _leagues = value; NotifyPropertyChanged("Leagues"); }
    }

    public async void Load()
    {
        string leaguesJSON = await ServerConnector.LoadOrganizations();

        Leagues.Clear();
        Leagues = JsonConvert.DeserializeObject<ObservableCollection<DataModels.League>>(leaguesJSON);
    }

I’ve tried setting the ObservableCollection’s to IList/ICollection’s to no avail.

edit: Here is the json that I am parsing: http://pastebin.com/QVnikitV

Answer 1

Your positions field in the C# code represents a single object of type Position. Your JSON object’s positions field represents an array.

So your C# code would need to be changed to an array to match:

public Position[] positions { get; set; }