Question

With reference to Parse JSON in C#

I am trying to parse the following JSON feed in C# and I have a problem with accessing the data in “rates”. I have tried to deserialize this into a List> or Dictionary and various other types I always get 0 results. The only way I managed to get it work was by creating a custom type and having all the currencies I need as properties – which is quite nice.

Here are my current DataContracts:

    [DataContract]
    public class OpenExchangeRatesResult
    {
        public OpenExchangeRatesResult() { }

        [DataMember]
        public string disclaimer { get; set; }

        [DataMember]
        public RatesObj rates { get; set; }

    }

    [DataContract]
    public class RatesObj
    {
        public RatesObj() { }
        [DataMember]
        public decimal EUR { get; set; }
        [DataMember]
        public decimal USD { get; set; }
        [DataMember]
        public decimal GBP { get; set; }
        [DataMember]
        public decimal AUD { get; set; }
        [DataMember]
        public decimal CAD { get; set; }
        [DataMember]
        public decimal CHF { get; set; }
        [DataMember]
        public decimal DKK { get; set; }
        [DataMember]
        public decimal LYD { get; set; }
        [DataMember]
        public decimal NZD { get; set; }
        [DataMember]
        public decimal SEK { get; set; }
        [DataMember]
        public decimal JPY { get; set; }
        [DataMember]
        public decimal ZAR { get; set; }
    }

I would love to be able to replace the RatesObj with a collection of some sort.

Any ideas?

Answer 1

I’m using JSON.net (documentation here), which is probably similar to the DataContractJsonSerializer, but I just replaced your RatesObj with a Dictionary<string,decimal>:

[DataContract]
public class OpenExchangeRatesResult
{
    public OpenExchangeRatesResult() { }
    [DataMember]
    public string disclaimer { get; set; }
    [DataMember]
    public Dictionary<string, decimal> rates { get; set; }
}

And my test code:

class Program
{
    static void Main(string[] args)
    {
        HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(@"https://raw.github.com/currencybot/open-exchange-rates/master/latest.json");
        wr.Timeout = 30 * 1000;
        HttpWebResponse response = (HttpWebResponse)wr.GetResponse();
        using (var s = new StreamReader(response.GetResponseStream()))
        {
            string json = s.ReadToEnd();

            var oerr = JsonConvert.DeserializeObject<OpenExchangeRatesResult>(json);

            Console.WriteLine(json);
        }
    }
}

I end up with the rates property having some 150 entries of strings (the currency name) and decimals (the rates). Hopefully this is what you’re looking for.

I hope this helps. Let me know if you have other questions and I’ll elaborate my answer.

Good luck!