public DataTemplateTestViewModel(IPageDialogService pageDlg)
        {
            ItemsSource = new ObservableCollection <Person>(
                new List <Person>
            {
                new Person {
                    Name = "ABC", Days = "1,2,3,4"
                },
                new Person {
                    Name = "DEF", Days = "5,6,7,8"
                },
            }
                );

            DoCommand.Subscribe(async _ => {
                await pageDlg.DisplayAlertAsync("", "Command", "OK");
            });

            AddCommand.Subscribe(_ => {
                ItemsSource.Add(new Person {
                    Name = "Add", Days = "9,9,9,9"
                });
            });

            DelCommand.Subscribe(_ => {
                ItemsSource.Remove(ItemsSource.Last());
            });

            RepCommand.Subscribe(_ => {
                ItemsSource[0] = new Person {
                    Name = "Rep", Days = "1,1,1,1"
                };
            });

            ClrCommand.Subscribe(_ => {
                ItemsSource.Clear();
            });

            BtmCommand.Subscribe(_ => {
                ScrollToBottom.Value = true;
            });

            TopCommand.Subscribe(_ => {
                ScrollToTop.Value = true;
            });
        }