Read in a JSON Array and convert to a IEnumerable

Question

I've never worked with JSON files but I have the task to implement the JSON file and I need to convert it to a IEnumerable. When I try to deserzialize the JSON object I get an exception which says:

An unhandled exception of type 'Newtonsoft.Json.JsonSerializationException' occurred in Newtonsoft.Json.dll

Additional information: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'Price_Algorithm.AuctionInfo' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

My code:

var data = File.ReadAllText(@"C:\benatia.json");
var terry = JsonConvert.DeserializeObject<IEnumerable<AuctionInfo>>(data);

public class AuctionInfo : IEnumerable
{
    public string BidState { get; set; }
    public uint BuyNowPrice { get; set; }
    public uint CurrentBid { get; set; }
    public int Expires { get; set; }
    public ItemData ItemData { get; set; }
    public uint StartingBid { get; set; }
    public string TradeState { get; set; }

    public IEnumerator GetEnumerator()
    {
        throw new NotImplementedException();
    }
}

I've uploaded the JSON object so everyone knows the content of the whole JSON file: http://puu.sh/fancH/9a495ecbe9.json (new JSON)

Answer 1

Using json2csharp.com the classes you should be deserializing into should look like this:

public class AttributeList
{
    public int Index { get; set; }
    public int Value { get; set; }
}

public class LifeTimeStat
{
    public int Index { get; set; }
    public int Value { get; set; }
}

public class StatsList
{
    public int Index { get; set; }
    public int Value { get; set; }
}

public class ItemData
{
    public int AssetId { get; set; }
    public int Assists { get; set; }
    public List<AttributeList> AttributeList { get; set; }
    public int CardSubTypeId { get; set; }
    public int Contract { get; set; }
    public int DiscardValue { get; set; }
    public int Fitness { get; set; }
    public string Formation { get; set; }
    public object Id { get; set; }
    public int InjuryGames { get; set; }
    public string InjuryType { get; set; }
    public string ItemState { get; set; }
    public string ItemType { get; set; }
    public int LastSalePrice { get; set; }
    public int LeagueId { get; set; }
    public int LifeTimeAssists { get; set; }
    public List<LifeTimeStat> LifeTimeStats { get; set; }
    public int LoyaltyBonus { get; set; }
    public int Morale { get; set; }
    public int Owners { get; set; }
    public int PlayStyle { get; set; }
    public string PreferredPosition { get; set; }
    public int RareFlag { get; set; }
    public int Rating { get; set; }
    public int ResourceId { get; set; }
    public List<StatsList> StatsList { get; set; }
    public int Suspension { get; set; }
    public int TeamId { get; set; }
    public string Timestamp { get; set; }
    public int Training { get; set; }
    public bool Untradeable { get; set; }
    public int Pile { get; set; }
}

public class RootObject
{
    public string BidState { get; set; }
    public int BuyNowPrice { get; set; }
    public int CurrentBid { get; set; }
    public int Expires { get; set; }
    public ItemData ItemData { get; set; }
    public int Offers { get; set; }
    public string SellerEstablished { get; set; }
    public int SellerId { get; set; }
    public string SellerName { get; set; }
    public int StartingBid { get; set; }
    public object TradeId { get; set; }
    public string TradeState { get; set; }
    public object Watched { get; set; }
}

I took the JSON from the link you posted, threw it into a file, and put together a little console application that does the following:

var data = File.ReadAllText("json1.json");
var auctions = JsonConvert.DeserializeObject<IEnumerable<RootObject>>(data);

Here's a link to the solution I built http://1drv.ms/1ChmYYx but it's really no more than what I already posted.

Worked perfectly, I got 26 instances of RootObject.

If you want you can rename RootObject to something else. I just cut-and-pasted directly from what json2charp generated.

Answer 2

Do this instead:

var data = "[" + File.ReadAllText(@"C:\benatia.json") + "]";
var terry = JsonConvert.DeserializeObject<IEnumerable<AuctionInfo>>(data);

Your JSON file is slightly malformed, since it contains multiple JSON objects separated by commas, but no surrounding square brackets [ ... ], which would define a JSON array.

I have added the square brackets to your data string.