private void RibbonBtnPersonMut_Click(object sender, RoutedEventArgs e)
        {
            PersonWindow pwin = new PersonWindow();
            var          collectionViewSource = pwin.FindResource("Teams") as CollectionViewSource;

            collectionViewSource.Source = context.Teams.ToList <Team>();

            Person p = PersonenListView.SelectedItem as Person;

            if (p == null)
            {
                this.ShowMessageAsync("Hinweis: Person mutieren", "Keine Person ausgewählt");
            }
            else
            {
                pwin.DataContext = p;
                pwin.ShowDialog();
                if (pwin.DialogResult.HasValue && pwin.DialogResult.Value)
                {
                    context.SaveChanges();
                }
                else
                {
                    context.Entry <Person>(p).State = EntityState.Unchanged;
                    PersonenListView.Items.Refresh();
                }
            }
        }
        private void RibbonBtnPersonNeu_Click(object sender, RoutedEventArgs e)
        {
            PersonWindow pwin      = new PersonWindow();
            Person       newPerson = new Person();

            pwin.DataContext = newPerson;
            var collectionViewSource = pwin.FindResource("Teams") as CollectionViewSource;

            collectionViewSource.Source = context.Teams.ToList <Team>();

            pwin.ShowDialog();
            if (pwin.DialogResult.HasValue && pwin.DialogResult.Value)
            {
                context.Personen.Add(newPerson);
                context.SaveChanges();
            }
            else
            {
            }
        }
        void PersonListViewItem_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            Person       p    = ((ListViewItem)sender).Content as Person;
            PersonWindow pwin = new PersonWindow();
            var          collectionViewSource = pwin.FindResource("Teams") as CollectionViewSource;

            collectionViewSource.Source = context.Teams.ToList <Team>();



            pwin.DataContext = p;
            pwin.ShowDialog();
            if (pwin.DialogResult.HasValue && pwin.DialogResult.Value)
            {
                context.SaveChanges();
            }
            else
            {
                context.Entry <Person>(p).State = EntityState.Unchanged;
                PersonenListView.Items.Refresh();
            }
        }