How to display JSON data (nested) in C#

Question

I am fetching an API that returns a JSON response like this:

{
"id": 161635,
"rev": 1,
"fields": {
  "System.Url": "http://google.com",
  "System.Type": "Bug",
  "System.State": "New",
  "System.AssignedTo": {
    "displayName": "John Doe"
    }
  }
}

I want to display the id and everything inside fields . This is my model:

public class WorkItemDetail {
  public int id { get; set; }
  public Dictionary<string, object> fields {get;set;}
}

Here is the problem, I can display the id and everything in fields except for some reason, I can't show displayName

Here is what I doing:

@WorkItemDetailResponse.id
@WorkItemDetailResponse.fields["System.WorkItemType"];  
@WorkItemDetailResponse.fields["System.State"]; 
@WorkItemDetailResponse.fields["System.AssignedTo"]; 
@WorkItemDetailResponse.fields["System.AssignedTo"]["displayName"]; <!-- does not work -->


@code{
 WorkItemDetailResponse = JsonConvert.DeserializeObject<WorkItemDetail>(ResponseBody); 
}

I am new to C# so I don't know why this line is not working

@WorkItemDetailResponse.fields["System.AssignedTo"]["displayName"]

Answer 1

Create your DTO structure as follows:

public class Fields
{
    [JsonProperty("System.Url")]
    public string SystemUrl { get; set; }

    [JsonProperty("System.Type")]
    public string SystemType { get; set; }

    [JsonProperty("System.State")]
    public string SystemState { get; set; }

    [JsonProperty("System.AssignedTo")]
    public SystemAssignedTo SystemAssignedTo { get; set; }
}

public class WorkItemDetail
{
    public int id { get; set; }
    public int rev { get; set; }
    public Fields fields { get; set; }
}

public class SystemAssignedTo
{
    public string displayName { get; set; }
}

here's fiddle: https://dotnetfiddle.net/F9Wppv

another way - using dynamic variable: https://dotnetfiddle.net/Goh7YY

Answer 2

You need to cast the object value to a JObject

((JObject)JsonConvert.DeserializeObject<WorkItemDetail>(json).fields["System.AssignedTo"])["displayName"]

JSON.Net will create a JObject if the property type is object and the value is a JSON object.

db<>fiddle