This function gets the parent `PropertyPageSite` Object using Reflection. It must be called in Load event.

**Visual Basic**



    Private Function GetPropertyPageSite() As Outlook.PropertyPageSite
        Dim objType As Type = GetType(System.Object)
        Dim assemblyPath As String = objType.Assembly.CodeBase.Replace("mscorlib.dll", "System.Windows.Forms.dll").Replace("file:///", "")
        Dim assemblyName As String = System.Reflection.AssemblyName.GetAssemblyName(assemblyPath).FullName

        Dim unsafeNativeMethods As Type = Type.[GetType](System.Reflection.Assembly.CreateQualifiedName(assemblyName, "System.Windows.Forms.UnsafeNativeMethods"))
        Dim oleObjectType As Type = unsafeNativeMethods.GetNestedType("IOleObject")

        Dim methodInfo As System.Reflection.MethodInfo = oleObjectType.GetMethod("GetClientSite")
        Dim propertyPageSite As Object = methodInfo.Invoke(Me, Nothing)

        Return DirectCast(propertyPageSite, Outlook.PropertyPageSite)
    End Function

**CSharp**



    private Outlook.PropertyPageSite GetPropertyPageSite()
    {
        Type objType  = typeof(System.Object);
        string assemblyPath = objType.Assembly.CodeBase.Replace("mscorlib.dll", "System.Windows.Forms.dll").Replace("file:///", "");
        string assemblyName = System.Reflection.AssemblyName.GetAssemblyName(assemblyPath).FullName;
        
        Type unsafeNativeMethods = Type.GetType(System.Reflection.Assembly.CreateQualifiedName(assemblyName, "System.Windows.Forms.UnsafeNativeMethods"));
        Type oleObjectType = unsafeNativeMethods.GetNestedType("IOleObject");
        
        System.Reflection.MethodInfo methodInfo = oleObjectType.GetMethod("GetClientSite");
        Object propertyPageSite = methodInfo.Invoke(this, null);
        
        return (Outlook.PropertyPageSite)propertyPageSite;
    }

From [How to implement OL PropertyPage][propertypage] / [Customize Outlook Options Dialog][customize]

[propertypage]: http://www.outlookcode.com/codedetail.aspx?id=978
[customize]: http://social.msdn.microsoft.com/Forums/vstudio/en-US/f7dd6f82-13e7-4a28-8316-9c535eaa7518/customize-outlook-options-dialog?forum=vsto#c45f5fb1-c15d-4a5e-bf0e-7cb677462fdd

The outlook [`PropertyPage`][PropertyPage] Interface requires a Read Only Boolean Property `Dirty`.  

When this is set to `true`, the Apply button from the property page options dialog will become enabled.

![Apply](http://i.imgur.com/JxKsTeZ.png)

According to this [walkthrough][walkthrough], you have to call [`OnStatusChange`][OnStatusChange] to notify the UI that the value of `Dirty` has changed.

Purportedly, this is available by calling the following:



    Dim ppSite As Outlook.PropertyPageSite = Parent
    ppSite.OnStatusChange()

But `Parent` always returns nothing so I have no mechanism to tell the UI when I have updated the dirty flag.

How can I do this?

---

I'm using the basic steps produced in this [discussion][discussion] to setup the options page.  
Here's a full implementation of my code:

### Added New User Control called `SendReminderOptions`:



    <ComVisible(True)>
    Public Class SendReminderOptions : Inherits UserControl : Implements Outlook.PropertyPage
    
        Const captionDispID As Integer = -518
    
        Private _dirty As Boolean = False
        Public ReadOnly Property Dirty As Boolean Implements Microsoft.Office.Interop.Outlook.PropertyPage.Dirty
            Get
                Return _dirty
            End Get
        End Property
    
        Public Sub SetDirty(newValue As Boolean)
            _dirty = newValue
            Dim ppSite As Outlook.PropertyPageSite = Parent
            ppSite.OnStatusChange()
        End Sub
    
        <DispId(captionDispID)> _
        Public ReadOnly Property PageCaption() As String
            Get
                Return "Send Reminder Options"
            End Get
        End Property
    
        Public Sub GetPageInfo(ByRef HelpFile As String, ByRef HelpContext As Integer) Implements Microsoft.Office.Interop.Outlook.PropertyPage.GetPageInfo
    
        End Sub
    
        Public Sub Apply() Implements Microsoft.Office.Interop.Outlook.PropertyPage.Apply
    
        End Sub
    
    End Class

### Added the following code to `ThisAddIn`



    Private Sub ThisAddIn_Startup() Handles Me.Startup
        Dim myOutlook As Outlook.Application = Globals.ThisAddIn.Application
        AddHandler myOutlook.OptionsPagesAdd, AddressOf AddOptionsPage
    End Sub

    Private Sub AddOptionsPage(ByVal pages As PropertyPages)
        pages.Add(New SendReminderOptions(), "Options")
    End Sub

[PropertyPage]: http://msdn.microsoft.com/en-us/library/microsoft.office.interop.outlook.propertypage.aspx
[discussion]: http://social.msdn.microsoft.com/Forums/vstudio/en-US/f7dd6f82-13e7-4a28-8316-9c535eaa7518/customize-outlook-options-dialog?forum=vsto#3e9cf09c-8056-46d3-bb09-2da019cf8ba6
[walkthrough]: http://msdn.microsoft.com/en-us/library/office/ff864286.aspx
[OnStatusChange]: http://msdn.microsoft.com/en-us/library/office/ff869275(v=office.14).aspx