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; }); }