vbdotnet Deserialize json to a class - json

Question

I am getting the below exception when deserializing a simple json text to a class. please help.
"Exception thrown: 'Newtonsoft.Json.JsonReaderException' in Newtonsoft.Json.dll
An unhandled exception of type 'Newtonsoft.Json.JsonReaderException' occurred in Newtonsoft.Json.dll
Unexpected character encountered while parsing value: [. Path 'Array1', line 4, position 14."
Below is the simple json text
{
"Name1": "Value1",
"Name2": "Value2",
"Array1":["a", "b", "c", "d"]
}
and below is the Class/Model
Public Class Test
Public Property Name1 As String
Public Property Name2 As String
Public Property Array1() As String
End Class
and below is the main module
Imports System
Imports System.IO
Imports System.Collections.Generic
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Serialization
Imports Newtonsoft.Json.Converters
Imports Newtonsoft.Json.Linq
Module Module1
Sub Main()
'Here I am reading all text from the json file to "strJsonText" and then the below line throws 'exception
Dim classDocs = JsonConvert.DeserializeObject(strJsonText, GetType(Test))
End Sub
End Module

Answer 1

Visual Studio has a cool feature called Paste JSON as Classes that can be found under Edit > Paste Special > Paste JSON as Classes. Using this feature produces the same results you have, I wanted to share this with you because it is a nice feature to know about nonetheless.
With regards to your actual problem, the issue is where the parenthesis are in your array declaration. In Visual Basic .NET, the parenthesis are implicit in property definitions. That means that these two property definitions are functionally equivalent:
Public Property Name1() As String
' or
Public Property Name1 As String
This gets a bit confusing because an array variable can be declared as such:
Dim Array1() As String
But when you try to convert this to a property, you have to move the parenthesis to the end to compensate for the parenthesis in property definitions.
What I would suggest doing is changing your array definition to an IEnumerable instead and then explicitly cast it to an array if you need to. In other words, something like this:
Public Class Test
Public Property Name1 As String
Public Property Name2 As String
Public Property Array1 As IEnumerable(Of String)
Public Shared Function ParseJson(literal As String)
Return JsonConvert.DeserializeObject(Of Test)(literal)
End Function
End Class
Example: https://dotnetfiddle.net/DVgpI3

Answer 2

You are declaring this property wrong, it is actually a String type not an array, and it has an empty parameter section.
Public Property Array1() As String
It should be an array of strings
Public Property Array1 As String()
Furthermore, you should use the generic version of DeserializeObject
Dim classDocs = JsonConvert.DeserializeObject(Of Test)(strJsonText)
dotnetfiddle

Answer 3

You need to add Test class in your Json so you can deserialize
'Test': [
{
'Name1': 'Value1',
'Name2': 'Value2',
'Array1': [
'a',
'b',
'c',
'd'
]
]
}