Hi all

Probably a newbe question but I can't get this to work. I am trying to consume an API return nested json. I have tried the following code and get this error.

Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[m2m.Model.DetailsHeader]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

            HttpClient client = new HttpClient();
            client.BaseAddress = new Uri(url);
            var response = await client.GetAsync(client.BaseAddress);
            response.EnsureSuccessStatusCode();
            var JsonResult = response.Content.ReadAsStringAsync().Result; // I have confirmed that the raw json is in JsonResult.
            
            var promotemp = JsonConvert.DeserializeObject<List<DetailsHeader>>(JsonResult);

namespace m2m.Model
{
    }

    public class DetailsHeader
    {
        public int autocouponlinkpk { get; set; }
        public DateTime enddate { get; set; }
        public string market_descrp { get; set; }
        public string globallogo { get; set; }
        public List<PromoDetails> details { get; set; }
    }

    public class PromoDetails
    {
        public long autocouplinkpage2pk { get; set; }
        public string image_fullurl { get; set; }
        public string group_descrp { get; set; }
    }
}

and here is the json

{
  "autocouponlinkpk": 170,
  "enddate": "2016-06-30",
  "market_descrp": "My test",
  "globallogo": "http://subscriberimages/47/fkpzlkxift-1423092258.jpg",
  "details": [
    {
      "autocouplinkpage2pk": 82,
      "image_fullurl": "http://marketImgs/47/xhkppjcxey-1445635420.png",
      "group_descrp": "This is page 2"
    },
    {
      "autocouplinkpage2pk": 83,
      "image_fullurl": "http://marketImgs/47/movjznnosp-1445700931.jpg",
      "group_descrp": "page 2 of page 2."
    },
    {
      "autocouplinkpage2pk": 84,
      "image_fullurl": "http://marketImgs/47/vbzkznsbkg-1445700969.jpg",
      "group_descrp": "page 3 of page 2"
    }
  ]
}

What am I doing wrong?

Thanks.