private void btnExisting_Click(object sender, RoutedEventArgs e)
{
if (SelectedExistingTask != null && !string.IsNullOrWhiteSpace(_status.CurrentContextId))
{
_taskService.AddContext(SelectedExistingTask.Id.ToString(), _status.CurrentContextId);
if (null != this.PropertyChanged)
{
PropertyChanged(this, new PropertyChangedEventArgs(Utils <ViewContextPage> .MemberName(s => s.ContextTasks)));
}
}
}
