Public Class Form1
    Dim f2 As Form2
    Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e _
      As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        For i = 1 To 10
            If BackgroundWorker1.CancellationPending Then
                e.Cancel = True
                Return
            End If
            Debug.WriteLine("DoWork running")
            System.Threading.Thread.Sleep(500)
        Next
    End Sub
 
    Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, _
      ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles _
      BackgroundWorker1.RunWorkerCompleted
        Debug.WriteLine("BGW ended")
        If f2 IsNot Nothing Then f2.Dispose()
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        BackgroundWorker1.RunWorkerAsync()
        f2 = New Form2
        f2.ShowDialog()
        f2 = Nothing
    End Sub
End Class

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