JSON <NonSerialized()> not working VB.NET? - json

Question

I'm having a bit of trouble with some JSON serialization that I'm doing in VB.NET.
Basically, I have two classes.
MenuItemDataLong
And MenuItemDataShort
MenuItemDataLong inherits MenuItemDataShort.
Code:
MenuItemDataShort.vb
<Serializable()>
Public Class MenuItemDataShort
Public Display_Name As String = ""
Public Display_Description As String = ""
Public Display_Price As Single = 0.0
Public SELECTED_NAME As Integer = 0
Public SELECTED_PRICE As Integer = 0
Public WEB_IMAGE As String = ""
Public WEB_IMAGE_WIDTH As Integer = 0
Public WEB_IMAGE_HEIGHT As Integer = 0
Public PAGE_NUM As Integer = 0
Public CELL_ID As Integer = 0
Public SHOW_BMP_FILE As Boolean = False
Public SHOW_DESCRIPT As Boolean = False
Public SHOW_PRICE As Boolean = False
Public SHOW_LONG_DESC As Boolean = False
Public LONG_DESC_FONT_NAME As String
Public LONG_DESC_FONT_BOLD As Boolean
Public LONG_DESC_FONT_UNDERLINE As Boolean
Public LONG_DESC_FONT_ITALIC As Boolean
Public LONG_DESC_FONT_COLOR_R As Integer
Public LONG_DESC_FONT_COLOR_G As Integer
Public LONG_DESC_FONT_COLOR_B As Integer
Public LONG_DESC_FONT_SIZE As Integer
Public DESC_FONT_NAME As String
Public DESC_FONT_BOLD As Boolean
Public DESC_FONT_UNDERLINE As Boolean
Public DESC_FONT_ITALIC As Boolean
Public DESC_FONT_COLOR_R As Integer
Public DESC_FONT_COLOR_G As Integer
Public DESC_FONT_COLOR_B As Integer
Public DESC_FONT_SIZE As Integer
Public PRICE_FONT_NAME As String
Public PRICE_FONT_BOLD As Boolean
Public PRICE_FONT_UNDERLINE As Boolean
Public PRICE_FONT_ITALIC As Boolean
Public PRICE_FONT_COLOR_R As Integer
Public PRICE_FONT_COLOR_G As Integer
Public PRICE_FONT_COLOR_B As Integer
Public PRICE_FONT_SIZE As Integer
Public DESC_X As Integer
Public DESC_Y As Integer
Public PRICE_X As Integer
Public PRICE_Y As Integer
Public IMAGE_X As Integer
Public IMAGE_Y As Integer
Public LONG_DESC_X As Integer
Public LONG_DESC_Y As Integer
End Class
MenuItemDataLong.vb
<Serializable()>
Public Class MenuItemDataLong
Inherits MenuItemDataShort
<NonSerialized()>
Public DESCRIPT As String
<NonSerialized()>
Public OO_Alias As String
<NonSerialized()>
Public LONG_DESCRIPTION As String
<NonSerialized()>
Public RECIPE_DESCRIPTION As String
<NonSerialized()>
Public BMP_FILE As String
<NonSerialized()>
Public PRICE1, PRICE2, PRICE3, PRICE4, PRICE5, PRICE6, PRICE7, PRICE8, PRICE9, PRICE10, PRICE11, PRICE12, PRICE13, PRICE14 As Single
End Class
I then have the MenuItemDataLong object stored somewhere. The excess data in the MenuItemDataLong class is necessary in application, but is not necessary once the file is serialized. So, I'm trying to take the MenuItemDataLong and cast it back down to a MenuItemDataShort and serialize it. However, Whenever I do I end up with all of the data from MenuItemDataLong still in it, even with the NonSerialized() tags.
Anyone know what I'm doing wrong?..
EDIT:
If anyone is curious, this is how I'm serializing:
Dim sItemData As MenuItemDataShort = CType(ItemData, MenuItemDataShort)
Dim Serializer As New System.Web.Script.Serialization.JavaScriptSerializer
Dim Serialized As String = Serializer.Serialize(sItemData)

Answer 1

You are basically using the wrong attribute. From MSDN - NonSerialized:
When using the BinaryFormatter or SoapFormatter classes to serialize an object, use the NonSerializedAttribute attribute to prevent a field from being serialized.
It does not mention the JavaScriptSerializer. There is another attribute: <ScriptIgnore> which seems to work. Using simplified classes and a mix of actual Properties and Fields:
Imports System.Web.Script.Serialization
<Serializable()>
Public Class MenuItemShort
Public Property Name As String = ""
Public Description As String = ""
End Class
<Serializable()>
Public Class MenuItemLong
Inherits MenuItemShort
<ScriptIgnore>
Public Property Foo As String
<ScriptIgnore>
Public Bar As String
Public Property Value As Integer
End Class
Test Code:
Dim mi As New MenuItemLong With {.Name = "foo",
.Description = "a foo item",
.Foo = "ghost in the machine",
.Bar = "bar",
.Value = 42}
Dim miS As MenuItemShort = DirectCast(mi, MenuItemShort)
Dim jser As New System.Web.Script.Serialization.JavaScriptSerializer
Dim jss As String = jser.Serialize(miS)
Console.WriteLine(jss)
Output:
{"Description":"a foo item","Value":42,"Name":"foo"}
There are other ways to ignore certain properties using NewtonSoft's JSON.Net.