Convert vb.net class object to JSON string in vb.net

Question

I am a c# developer and have the requirement to work in vb.net project. I am facing a simple issue I need to convert a class object to json string in vb.net.Problem is when I check the string after conversion I am getting output as:

[{},{},{}]

I am trying to store value of 3 objects into it but I am getting 3 empty objects {}. My code is like this:

Imports System.Web.Script.Serialization

Partial Class test
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim serializer As New JavaScriptSerializer
        Dim msgObj As msg
        Dim loginList As New List(Of msg)()

        msgObj = New msg("mubashir", True)
        loginList.Add(msgObj)
        msgObj = New msg("yasir", False)
        loginList.Add(msgObj)
        msgObj = New msg("umar", True)
        loginList.Add(msgObj)
        Dim s As String = serializer.Serialize(loginList)
        Response.Write(s)

    End Sub
End Class
Public Class msg
    Dim message As String
    Dim status As Boolean
    Sub New(ByRef Messag As String, ByVal Stat As Boolean)



        Me.message = Messag
        Me.status = Stat

    End Sub
End Class

score 5 · Accepted Answer · answered May 12 '15 at 09:17

5

message, status need to declare as Property.

Public Class msg
      Public Property message() As String
      Public Property status() As Boolean
      Sub New(ByRef Messag As String, ByVal Stat As Boolean)
            Me.message = Messag
            Me.status = Stat    
      End Sub
End Class

answered May 12 '15 at 09:17

Nguyen Kien

1,897
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Its working, thx Nguyen Kien...but may I know reason why it wasnot working. I think private class members are not serialized. – killer May 12 '15 at 09:21
1

Of course, private member is not serialize, even in c# – Nguyen Kien May 12 '15 at 09:25

score 2 · Answer 2 · answered May 12 '15 at 09:18

It looks like it's your msg class at fault here, as you have declared two fields rather than two properties:

Public Class msg
    Public Property message() As String
    Public Property status() As Boolean
    Sub New(ByRef Messag As String, ByVal Stat As Boolean)
        Me.message = Messag
        Me.status = Stat

    End Sub
End Class

Convert vb.net class object to JSON string in vb.net

2 Answers2