create c# object from json array

Question

I am receiving an error when trying to convert my json array into an object.

I have a Json array with multiple layers like this :

 { 
 "error":"0",
 "result":{ 
 "activities":{ 
 "1":{ 
 "activity_id":"15803",
 "activity_id_name":"Ashtanga vinyasa",
 "schedule":{ 
 "1":{ 
 "available":"30",
 "start":"09:00:00"
 }
 }
 },
 "2":{ 
 "activity_id":"15804",
 "activity_id_name":"Yin/Yang",
 "schedule":{ 
 "1":{ 
 "available":"30",
 "start":"10:30:00"
 }
 }
 },
 "3":{ 
 "activity_id":"15805",
 "activity_id_name":"Stress relief",
 "schedule":{ 
 "1":{ 
 "available":"30",
 "start":"20:00:00"
 }
 }
 }
 },
 "json_code":"2"
 },
 "id":null
}

From this i created an object that looks like this :

namespace LesRooster.Models
{
 public class JsonGroup
 {
 public string Error { get; set; }
 public List<Results> Result { get; set; }
 public string Id { get; set; }
 }
 public class Results
 {
 public Activities YogaActivities { get; set; }
 public int JsonCode { get; set; } 
 }
 public class Activities
 {
 public int ActivityId { get; set; }
 public string ActivityIdName { get; set; }
 public Schedule LesSchedule { get; set; }
 }
 public class Schedule
 {
 public int Available { get; set; }
 public DateTime Start { get; set; }
 }
}

When I try to add the array to the object with the following line :

JsonGroup jgroup = JsonConvert.DeserializeObject<JsonGroup>(JsonArrayCode);

I am receiving the following error :

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

Is there any way to resolve this? I would like to keep it as an object since it is easy to pass on in the view in my mvc5 application.

I have tried googling this but all solutions I have found are for single dimension json arrays.

The documentation of the API I request the json array from looks as follows :

json_code integer 
Constant value: 2
activities hash 
 {
 index : {
 activity_id: integer
 activity_id_name: string
 schedule: hash
 {
 index : {
 available: integer
 start: time
 }
 }
 }
}

• Matt Burland: The error is exactly what it says it is. In your JSON you have a property result that contains an object, with a property activities with a bunch more properties. That is not an array, so how is it supposed to deserialize it to one? You can either deserialize activities to a dictionary, or you can write your own converter to handle that property.
• eocron: You don't have collections in JSON message but do have in DT object.

Answer 1

The structure of your classes does not match the structure of the JSON - this results in an exception. I have made some changes to your classes to reflect the JSON structure.

The main difference is that Activities is not an Array but a Dictionary.

namespace LesRooster.Models
{
 public class JsonGroup
 {
 public string Error { get; set; }
 public Result Result { get; set; }
 public string Id { get; set; }
 }
 public class Result {
 public IDictionary<string, Activities> Activities {get; set;}
 public int JsonCode {get; set;}
 } 
 public class Activities
 {
 [JsonProperty("activity_id")]
 public int ActivityId { get; set; }
 [JsonProperty("activity_id_name")]
 public string ActivityIdName { get; set; }
 public IDictionary<string, Schedule> Schedule { get; set; }
 }
 public class Schedule
 {
 public int Available { get; set; }
 public DateTime Start { get; set; }
 } 
}

• Ňɏssa Pøngjǣrdenlarp: Schedule is a collection too
• Ralf Bönning: @Plutonix: Thanx - rather it is a Dictionary as well. I will update my answer. I am just checking if DateTime for Start is the proper type.
• Raphaël Althaus: Just think you need to put a [JsonProperty("activity_id_name")] on ActivityIdName property and [JsonProperty("activity_id")] on ActivityId property, or use something like this : migara.li/2016/01/09/json-net-easy-serialization
• Niels Peeren: Thanks a bunch @rboe !! this did the trick, DateTime appears to be working so it should be the right type.
• Raphaël Althaus: And your dictionaries could be of type <int, ...> (instead of string)

Answer 2

Have you tried JSON.NET ? it's MIT licenced BTW.

• Johan Buret: This answer fails to adress the discrepancy between the code and the recieved JSON message.