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private void Button_Click(object sender, RoutedEventArgs e)
{
if (button.Content == "Start")
{
button.Content = "Stop";
cts.Dispose(); // Clean up old token source....
cts = new CancellationTokenSource(); // "Reset" the cancellation token source...
DoWork(cts.Token);
}
else
{
button.Content = "Start";
cts.Cancel();
}
}