public override void Execute(object parameter = null) { if (parameter is Fluent.ToggleButton) { ToggleButton = (ToggleButton)parameter; } OpenFileDialog ofd = new OpenFileDialog { DefaultExt = ".eXoL", Filter = "eXolutio log files (*.eXoL)|*.eXoL|XML files (*.xml)|*.xml|All files (*.*)|*.*||" }; if (ofd.ShowDialog() == true) { CommandLogger.LoadLogFile(ofd.FileName); } }