//File:Window.xaml.vb Imports System.Windows Namespace WpfApplication1 Public Partial Class Window1 Inherits Window Public Sub New() InitializeComponent() End Sub Private Sub ButtonTrue_Click(sender As Object, e As RoutedEventArgs) Me.Dispatcher.VerifyAccess() End Sub Private Sub ButtonFalse_Click(sender As Object, e As RoutedEventArgs) Dim del As New VerifyAccessDelegate(AddressOf VerifyAccess) del.BeginInvoke(Nothing, Nothing) End Sub Private Delegate Sub VerifyAccessDelegate() Private Overloads Sub VerifyAccess() Me.Dispatcher.VerifyAccess() End Sub End Class End Namespace