JsonConvert.DeserializeObject在.net中不起作用

Question

I am not getting JsonConvert.DeserializeObject to work for me. I get the correct value in JSON from the service. Not finding anything online for this, would appreciate a little help here :)

Here is my code:

public partial class _Default : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void tbPlate_OnServerChange(object sender, EventArgs e)
    {
        if (!string.IsNullOrEmpty(tbPlate.Text))
        {
            var _res = Responses(tbPlate.Text);

            if (_res.Vehicles != null)
            {
                lblTestText.Text = _res.Vehicles.FirstOrDefault(r => r.regNr == tbPlate.Text)?.ToString();
            }
            else
            {
                lblTestText.Text = "No vehicle data"; 
            }
        }
    }

    private static VehicleResults Responses(string regNr)
    {
        var _jSon = "";
        var _url = @"http://apis.is/car";
        var _res = new VehicleResults();

        var _request = (HttpWebRequest)WebRequest.Create($"{_url}?number={regNr}");

        var _response = _request.GetResponse();

        using (var _responseStream = _response.GetResponseStream())
        {
            var _reader = new StreamReader(_responseStream, Encoding.UTF8);
            _jSon = _reader.ReadToEnd();
        }

        _res = JsonConvert.DeserializeObject<VehicleResults>(_jSon);
        return _res;
    }
}

public class VehicleResponse
{
    [JsonProperty("registryNumber")]
    public string regNr { get; set; }
    public string number { get; set; }
    public string factoryNumber { get; set; }
    public string type { get; set; }
    public string subType { get; set; }
    public string color { get; set; }
    public string registeredAt { get; set; }
    public string status { get; set; }
    public string nextCheck { get; set; }
    public string pollution { get; set; }
    public string weight { get; set; }
}

public class VehicleResults
{
    public List<VehicleResponse> Vehicles { get; set; }
}

This is the response JSON from the service:

{"results":[{"type":"MERCEDES BENZ - M (Svartur)","subType":"M","color":"Svartur","registryNumber":"GXS56","number":"GXS56","factoryNumber":"WDC1631131A539035","registeredAt":"23.09.2004","pollution":" g/km","weight":"2200 kg","status":"Í lagi","nextCheck":"01.06.2019"}]}

I am quite new to REST services so I believe that the problem is small....I am just not able to figure it out right now.

Answer 1

Your json has a root object that contains the list of your vehicles.
You need to name the variable that holds your list with the name returned in the json. results

public class VehicleResults
{
    // This should be named results
    public List<VehicleResponse> results {get;set;}
}

Now you can deserialize with

VehicleResults data = JsonConvert.DeserializeObject<VehicleResults>(json);
foreach(var vei in data.results)
   Console.WriteLine(vei.type);

Answer 2

You need to [JsonProperty] on every property in VehicleResponse

Please add _reader.Close() at the end of the using