private string ExportToString(AppAppointment exportApp)
{
ObservableCollection<AppAppointment> ap = new ObservableCollection<AppAppointment>();
ap.Add(exportApp);
StringBuilder builder = new StringBuilder();
using (TextWriter writer = new StringWriter(builder)) {
AppointmentCalendarExporter exporter = new AppointmentCalendarExporter();
exporter.Export(ap.OfType<IAppointment>(), writer);
}
return builder.ToString();
}
