Creating Property in My.MySettings

Question

I want to create a global setting that I can do some program specific validation against.
In the Project/Properties/Settings tab there is a button on top which says "View Code". If you click on it, it generates the following code in a Settings.vb file.
Namespace My
    'This class allows you to handle specific events on the settings class:
    ' The SettingChanging event is raised before a setting's value is changed.
    ' The PropertyChanged event is raised after a setting's value is changed.
    ' The SettingsLoaded event is raised after the setting values are loaded.
    ' The SettingsSaving event is raised before the setting values are saved.
    Partial Friend NotInheritable Class MySettings
    End Class
End Namespace
If I add a property into this class, and then try to use it in my program via My.MySettings., my property does not come up. Why is that?
While I can probably do what I want to do in a regular class, I just want to know why it doesn't work when I do it via My.MySettings.

Answer 1

In regards to validation say on a value changed we can subscribe to several events.
Working example
Events
Here is a simple demo
Namespace My
Partial Friend NotInheritable Class MySettings
Inherits Global.System.Configuration.ApplicationSettingsBase
Private Sub MySettings_SettingChanging(
ByVal sender As Object,
ByVal e As System.Configuration.SettingChangingEventArgs) _
Handles Me.SettingChanging
Try
If (e.SettingName.Equals("NextBackup")) Then
Dim NewDate As Date = CType(e.NewValue, Date)
If (NewDate > Date.Now) Then
e.Cancel = False
Else
e.Cancel = True
MessageBox.Show("Can not use a past date")
End If
ElseIf (e.SettingName.Equals("PromptForExit")) Then
Dim NewPrompt As Boolean = CType(e.NewValue, Boolean)
If Not NewPrompt Then
If MsgBox("Are you sure not to prompt users on exit?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
e.Cancel = False
Else
e.Cancel = True
End If
End If
ElseIf (e.SettingName.Equals("MyName")) Then
Dim CurrentName As String = CType(e.NewValue, String)
If CurrentName = "Enter name here" Then
' Your logic says not to use perhaps since this is the initial setting
ElseIf CurrentName.Trim.Length > 8 OrElse CurrentName.LastIndexOf(" "c) > 0 Then
MessageBox.Show("Length of name must be under 8 characters without any spaces")
e.Cancel = True
Else
e.Cancel = False
End If
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
End Class
End Namespace
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