How to iterate through all keys of json node - json

Question

I'm trying to scrap the key values from this website API and it seems the json format it's not an array.
I'm working with console .Net core 6.0 using System.Text.Json.Nodes
The code I'm using is :
Dim streamData As Stream = Nothing
Using http As HttpClient = New HttpClient
Dim url As String = "https://api.hotbit.io/api/v1/market.status24h"
Dim t As Task(Of Stream) = http.GetStreamAsync(url)
streamData = t.Result
End Using
Dim jsonResponse As JsonNode = JsonNode.Parse(streamData)
Dim jsonData As JsonNode = jsonResponse("result")
Dim c As String = String.Empty
For Each jsonCurrency As JsonNode In jsonData.AsObject
c += jsonCurrency("last").ToString + " "
Next
but I get the error:
Cannot convert type 'KeyValuePair(Of String, JsonNode)' in JsonNode
What Am I doing wrong?
Thanks

Answer 1

Create a class to represent your JSON, like this:
Public Class MarketStatus
Public Property IsChange As Boolean
Public Property period As Integer
Public Property open As String
Public Property last As String
Public Property high As String
Public Property low As String
Public Property volume As String
Public Property deal As String
Public Property close As String
Public Property base_volume As String
Public Property quote_volume As String
End Class
Public Class Payload
Public Property _error As Object
Public Property result As Result
Public Property id As Integer
End Class
Public Class Result
<JsonPropertyName("0xBTCBTC")>
Public Property _0xBTCBTC As MarketStatus
<JsonPropertyName("0xBTCETH")>
Public Property _0xBTCETH As MarketStatus
<JsonPropertyName("0xCASHUSDT")>
Public Property _0xCASHUSDT As MarketStatus
<JsonPropertyName("1INCH1D3LUSDT")>
Public Property _1INCH1D3LUSDT As MarketStatus
' etc...
End Class
Now you can deserialize the entire payload by using JsonSerializer.Deserialize or JsonSerializer.DeserializeAsync:
Dim payloadObject = Await JsonSerializer.DeserializeAsync(Of Payload)(streamData)
Update
Per our conversation in the comments of this answer, you want to get the last value of each MarketStatus without having to type each one manually. What you can do is:
Use reflection to get every property of the Result class
Loop over the collection
Use PropertyInfo.GetValue to get the value of the deserialized object
Here is an example using the same variable names as above:
For Each propertyInformation In GetType(Result).GetProperties()
Dim status = DirectCast(propertyInformation.GetValue(payloadObject.result), MarketStatus)
Console.WriteLine("{0}.last = {1}", propertyInformation.Name, status.last)
Next
Fiddle: https://dotnetfiddle.net/USaAgc

Answer 2

I solved using
Dim result As JsonObject = jsonResponse("result").AsObject
For Each kvp In result.AsEnumerable
c &= kvp.Value("last").ToString & ", "
Next