如何使用嵌套列表反序列化Json

Question

It's not my first time deserializing Json into c# classes but I am having some trouble when these Json have nested lists. Here is the returned Json of a list of workOrders:

[
  {
    "_id": "5cacdda0b4e6d128a61187ca",
    "taskInstance": [
      {
        "_id": "5cacdda0b4e6d128a61187cc"
      }
    ],
    "isRunning": false
  },
  {
    "_id": "5cacebb0b4e6d128a61187d1",
    "taskInstance": [
      {
        "_id": "5cacebb0b4e6d128a61187d3"
      }
    ],
    "isRunning": false
  }
]

and here the C# classes: WorkOrder

public class WorkOrder{
    public string Id { get; set; }
    public List<TaskInstance> TaskInstances { get; set; }
    public string IsRunning { get; set; }
}

and TaskInstance

public class TaskInstance{
    public string Id { get; set; }
}

And here is the code that I'm using to check the result:

JObject jsonResponse = JObject.Parse(data["data"].ToString());
string workOrderJson = jsonResponse["workOrderInstances"].ToString();
List<WorkOrder> wos = JsonConvert.DeserializeObject<List<WorkOrder>>(workOrderJson);

foreach (WorkOrder wo in wos){
    Debug.Log("WO _id: " + wo.Id);
    Debug.Log("wo.TaskInstances: "+ wo.TaskInstances);
    Debug.Log("WO isRunning: " + wo.IsRunning);
}

And while I'm seeing the correct values for WO._id and WO.isRunning wo.TaskInstances seems to be returning null or at leat throws a null reference exception whenever I try to access it.

I've searched other topics before but none of the solutions seem to work. I'm not sure what I am missing. Thank you for your help.

Disclaimer: the raw data in JObject.Parse(data["data"] looks like this:

{
  "data": {
    "workOrderInstances": [
      {
        "_id": "5cacdda0b4e6d128a61187ca",
        "taskInstance": [
          {
            "_id": "5cacdda0b4e6d128a61187cc"
          }
        ],
        "isRunning": false
      },
      ...
     ]
  }
}

Answer 1

Use this model:

Because the problem with your model is: JSON property name and model property name is not the same in your code.

So whenever you need your own custom name in property use
[JsonProperty("JsonPropertyName")]

 public partial class Root
    {
        [JsonProperty("_id")]
        public string Id { get; set; }

        [JsonProperty("taskInstance")]
        public TaskInstance[] TaskInstances { get; set; }

        [JsonProperty("isRunning")]
        public bool IsRunning { get; set; }
    }

    public partial class TaskInstance
    {
        [JsonProperty("_id")]
        public string Id { get; set; }
    }

Let me know if it works for you.