Some bugs in Xamarin Forms 2.3.3

XF_2_3_3_ListView_iOS_bugs.cs

    public class ListViewPage : ContentPage
    {
        //Tree bugs (iOS):
        //1. Important. If spinner is running, and you press the Entry, then the listview will get unaligned.
        //     to reproduce. Just start the project, click the entry, and then click the Refresh button.
        //2. If changeExecute is changed while running, it will kill the spinner.
        //     to reproduce use pull to refresh, and se that the spinner disapairs before the list is updated.
        //3. If can execute returns false, the spinner will start, but the command will never execute.
        //     to reproduce, just uncomment "_canExecute = true;" and do a pull to refresh.
        readonly ListView _listView;

        private bool? _canExecute;

        readonly Command _refreshCommand;

        public ListViewPage()
        {
            this.Padding = new Thickness(0, 20, 0, 0);

            _canExecute = true; //Start bug 3 if commented out, and starts bug 2 if not.

            _refreshCommand = new Command(RefreshCommandLogic, () => _canExecute ?? false);
            _listView = new ListView
            {
                HeaderTemplate = new DataTemplate(() => {
                    return new StackLayout { Children = { new Label { Text = "Test 456" } } };
                }),
                Header = new StackLayout { Children = { new Label { Text = "Test 123" } } },
                IsPullToRefreshEnabled = true,
                IsRefreshing = true,
                RefreshCommand = _refreshCommand,
                ItemsSource = new string[0]
            };


            _listView.PropertyChanged += (sender, e) => {
                if (e.PropertyName == nameof(ListView.ItemsSource))
                    _listView.IsRefreshing = false;
            };

            Content = new StackLayout
            {
                Children = {
                    new Button { Text = "ClearView", Command = new Command(() => Application.Current.MainPage = new ListViewPage()) },
                    new Entry { Placeholder = "TestTExt" },
                    new Button { Text = "Toggle", Command = new Command(() => _listView.IsRefreshing = !_listView.IsRefreshing) },
                    new Button { Text = "Refresh", Command = new Command(() => {
                            _listView.IsRefreshing = true;
                            RefreshCommandLogic();
                        })
                    },
                    new Grid {
                        RowDefinitions = {
                            new RowDefinition { Height = 300 }
                        },
                        Children = {
                            _listView
                        }
                    }
                }
            };
        }

        private async void RefreshCommandLogic()
        {
            _listView.IsRefreshing = true;

            //Will kill spinner early:
            //It is a bug, but is this the correct way of using this? Should be => parameter == something, yes/no.
            //However, it will start the spinner, but not execute the command.
            if (_canExecute != null)
            {
                _canExecute = false;
                _refreshCommand.ChangeCanExecute();
            }

            await Task.Delay(2000);

            _listView.ItemsSource = Enumerable.Range(0, 1)
                                              .Select(i => Guid.NewGuid().ToString("N"))
                                              .ToArray();

            if (_canExecute != null)
            {
                _canExecute = true;
                _refreshCommand.ChangeCanExecute();
            }
        }
    }