'Json'是一种类型，不能用作表达式

Question

Dim sonuc = Request.QueryString("s")
Dim output As String = ""
Dim response = HPMHelper.GetResponse(Request.Form, "netahsilat")
If sonuc = "basarili" Then
    Dim a = JsonConvert.SerializeObject(Json(response))
    Dim ser As JObject = JObject.Parse(a)
    Dim data As List(Of JToken) = ser.Children().ToList

    Dim ss

    For Each item As JProperty In data
        'Code
    Next
End If

我在第5行得到错误：

  

“Json（response）”'Json'是一种类型，不能用作表达式

任何人都可以帮助我？