Deserialize this JSON string

Question

I always get the error:

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[Test.Form15+results[]]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.

Path 'result', line 1, position 10.

My code is as follows and i'm not sure if it's the double-quotes causing the issues, or the bracket at the start of the json string. Any tips would be appreciated.

Public Class Form15

Public Class UTicketContact

    <JsonProperty("display_value")>
    Public Property DisplayValue As String

    <JsonProperty("link")>
    Public Property Link As String
End Class

Public Class URequestedFor

    <JsonProperty("display_value")>
    Public Property DisplayValue As String

    <JsonProperty("link")>
    Public Property Link As String
End Class

Public Class AssignedTo

    <JsonProperty("display_value")>
    Public Property DisplayValue As String

    <JsonProperty("link")>
    Public Property Link As String
End Class

Public Class OpenedBy

    <JsonProperty("display_value")>
    Public Property DisplayValue As String

    <JsonProperty("link")>
    Public Property Link As String
End Class

Public Class AssignmentGroup

    <JsonProperty("display_value")>
    Public Property DisplayValue As String

    <JsonProperty("link")>
    Public Property Link As String
End Class

Public Class Result

    <JsonProperty("u_ticket_contact")>
    Public Property UTicketContact As UTicketContact

    <JsonProperty("u_requested_for")>
    Public Property URequestedFor As URequestedFor

    <JsonProperty("assigned_to")>
    Public Property AssignedTo As AssignedTo

    <JsonProperty("opened_by")>
    Public Property OpenedBy As OpenedBy

    <JsonProperty("assignment_group")>
    Public Property AssignmentGroup As AssignmentGroup
End Class

Public Class results

    <JsonProperty("result")>
    Public Property Result As Result()
End Class


Function FindRequestedFor(ByVal instancename As String,
                          ByVal rtask As String) As String

    Dim requestedfor As String = ""
    'Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)

    Dim accessToken As String = GenerateToken("instancenameredacted",
                                              "clientIdredacted",
                                              "clientSecretredacted",
                                              "accountredacted",
                                              "accountpasswordredacted")

    Dim url As String = "https://" & instancename & ".service-now.com/api/ubis2/request/rtask?query=number%3D" & rtask

    Dim request As WebRequest = WebRequest.Create(url)
    Dim dataStream As Stream

    request.ContentType = "application/json; charset=utf-8"
    request.Method = "GET"
    request.Headers.Add("Authorization", "Bearer " & accessToken)
    dataStream = request.GetResponse.GetResponseStream

    Dim reader As New StreamReader(dataStream)
    Dim responseFromServer As String = reader.ReadToEnd
'Format of the JSON string is:     ""{
  ""result"": [
    {
      ""u_ticket_contact"": {
        ""display_value"": ""Name1"",
        ""link"": ""https://instance.service-now.com/api/now/table/sys_user/470104cf600ad400808370bee6ad2596""
      },
      ""u_requested_for"": {
        ""display_value"": ""Name2"",
        ""link"": ""https://instance.service-now.com/api/now/table/sys_user/470104cf600ad400808370bee6ad2596""
      }, 
      ""assigned_to"": {
        ""display_value"": ""Name3"",
        ""link"": ""https://instance.service-now.com/api/now/table/sys_user/98c7a3e5ac723040773cf2044a10de0c""
      },
      ""opened_by"": {
        ""display_value"": ""Name4"",
        ""link"": ""https://instance.service-now.com/api/now/table/sys_user/470104cf600ad400808370bee6ad2596""
      },
      ""assignment_group"": {
        ""display_value"": ""Group Name1"",
        ""link"": ""https://instance.service-now.com/api/now/table/sys_user_group/bad979fa19c44a40b5a0d99e2b982e75""
      }
    }
  ]
}""
    Console.WriteLine(responseFromServer)

    reader.Close()
    dataStream.Close()

    Dim test = JsonConvert.DeserializeObject(Of List(Of results()))(responseFromServer)
End Function
end class

Answer 1

I would use List(Of Result) type with initialization as below:

Public Class results
    <JsonProperty("result")>
    Public Property Result As New List(Of Result)
End Class