void AppState_PropertyChanged(object sender, PropertyChangedEventArgs e) { if (e.PropertyName == "TraceEnabled") { if (AppState.TraceEnabled) { if (m_linguaTraceListener == null) { m_linguaTraceListener = new LinguaTraceListener(Dispatcher, WriteTraceLine); LinguaTrace.TraceSource.Listeners.Add(m_linguaTraceListener); } } else { if (m_linguaTraceListener != null) { LinguaTrace.TraceSource.Listeners.Remove(m_linguaTraceListener); m_linguaTraceListener = null; } } } }