TargetInvocationException in BackgroundWorker class

To avoid TargetInvocationException exception in BackgroundWorker class, in BackgroundWorker.RunWorkerCompleted event handler don't access RunWorkerCompletedEventArgs.Result property in case of user cancellation or exception.

void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if (!e.Cancelled && (null == e.Error))
    {
        this.labelResult.Text = e.Result as String;
    }
}