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    <p>Consider this as your base class:</p> <pre><code>Public Class First Public Event ThemeToUseChanged As EventHandler Public Event ThemeToUseChanging As EventHandler Public Property ThemeToUse() As String Get Return Me.m_themeToUse End Get Set(ByVal value As String) If (value &lt;&gt; Me.m_themeToUse) Then Me.OnThemeToUseChanging(EventArgs.Empty) Me.m_themeToUse = value Me.OnThemeToUseChanged(EventArgs.Empty) End If End Set End Property Protected Overridable Sub OnThemeToUseChanged(ByVal e As EventArgs) If (Not Me.ThemeToUseChangedEvent Is Nothing) Then Me.ThemeToUseChangedEvent.Invoke(Me, e) End If End Sub Protected Overridable Sub OnThemeToUseChanging(ByVal e As EventArgs) If (Not Me.ThemeToUseChangingEvent Is Nothing) Then Me.ThemeToUseChangingEvent.Invoke(Me, e) End If End Sub Private m_themeToUse As String End Class </code></pre> <p>And this class inherits everything from <code>First</code> class:</p> <pre><code>Public Class Second Inherits First End Class </code></pre> <p>Now you can add handles to both the <code>ThemeToUseChanged</code> event and the <code>ThemeToUseChanging</code> event of each object:</p> <pre><code>Public Class Form1 Public Sub New() Me.InitializeComponent() End Sub Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 'Test: Me._first.ThemeToUse = New Guid().ToString() End Sub Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click 'Test: Me._second.ThemeToUse = New Guid().ToString() End Sub Private Sub ThemeToUseChanged(sender As Object, e As EventArgs) Handles _first.ThemeToUseChanged, _second.ThemeToUseChanged If (sender Is Me._first) Then 'ThemeToUseChanged changed of type `First` ElseIf (sender Is Me._second) Then 'ThemeToUseChanged changed of type `Second` End If End Sub Private Sub ThemeToUseChanging(sender As Object, e As EventArgs) Handles _first.ThemeToUseChanging, _second.ThemeToUseChanging If (sender Is Me._first) Then 'ThemeToUseChanging changed of type `First` ElseIf (sender Is Me._second) Then 'ThemeToUseChanging changed of type `Second` End If End Sub Private WithEvents _first As New First Private WithEvents _second As New Second End Class </code></pre> <p>And if you consider a <code>Third</code> class inherits <code>Second</code>:</p> <pre><code>Public Class Third Inherits Second End Class </code></pre> <p>This is how you can loop through the inheritance chain:</p> <pre><code>Dim obj As First = New Third() Dim t As Type = obj.GetType() Do MsgBox(t.FullName) t = t.BaseType Loop Until (t.BaseType Is Nothing) </code></pre>
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    1. POHow do I 'follow' a property changing event up the inheritance ladder
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    1. USBjørn-Roger Kringsjå
    1. USBjørn-Roger Kringsjå
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    1. POHow do I 'follow' a property changing event up the inheritance ladder
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    1. COThank you Bjorn that's a very nice and elegant solution.
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      1. USDom Sinclair
    2. CO@DomSinclair I'm glad it helped! FYI: I've added some more info.
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