bool HandleBackRequest()
{
var currentPageType = ContentFrame.Content?.GetType();
if (!CanGoBackPageTypes.Contains(ContentFrame.Content.GetType()))
{
Debug.WriteLine($"{currentPageType.Name} からの戻る操作をブロック");
return(false);
}
if (_navigationService.CanGoBack())
{
var backNavigationParameters = BackParametersStack.ElementAtOrDefault(BackParametersStack.Count - 1);
{
var last = BackParametersStack.Last();
var parameters = GetCurrentNavigationParameter(); // GoBackAsyncを呼ぶとCurrentNavigationParametersが入れ替わる。呼び出し順に注意。
BackParametersStack.Remove(last);
ForwardParametersStack.Add(parameters);
}
_ = backNavigationParameters == null
? _navigationService.GoBackAsync()
: _navigationService.GoBackAsync(backNavigationParameters)
;
return(true);
}
else
{
_navigationService.NavigateAsync(nameof(Views.SourceStorageItemsPage));
}
return(false);
}
private void SetupBackButton()
{
var children = XamlUtilities.RecurseChildren(this);
var grids = children.OfType <Grid>();
var grid = grids.Single(x => x.Name == "TogglePaneTopPadding");
grid.Visibility = Visibility.Collapsed;
grid = grids.Single(x => x.Name == "ContentPaneTopPadding");
grid.RegisterPropertyChangedCallback(HeightProperty, (s, args) =>
{
if (grid.Height != 44d)
{
grid.Height = 44d;
}
});
grid.Height = 44d;
var child_buttons = children.OfType <Button>();
_togglePaneButton = child_buttons.Single(x => x.Name == "TogglePaneButton");
_togglePaneButton.RegisterPropertyChangedCallback(MarginProperty, (s, args) =>
{
if (_togglePaneButton.Margin.Top != 0)
{
_togglePaneButton.Margin = new Thickness(0, 0, 0, 32);
}
});
_togglePaneButton.Margin = new Thickness(0, 0, 0, 32);
_togglePaneButton.Focus(FocusState.Programmatic);
var parent_grid = _togglePaneButton.Parent as Grid;
parent_grid.Width = double.NaN;
parent_grid.ColumnDefinitions.Add(new ColumnDefinition {
Width = new GridLength(48)
});
parent_grid.ColumnDefinitions.Add(new ColumnDefinition {
});
parent_grid.RowDefinitions[0].Height = GridLength.Auto;
parent_grid.RowDefinitions[1].Height = GridLength.Auto;
_paneTitleTextBlock = new TextBlock
{
Name = "PaneTitleTextBlock",
Margin = new Thickness(8, 18, 0, 0),
FontSize = 15,
FontFamily = new FontFamily("Segoe UI Bold"),
TextWrapping = TextWrapping.NoWrap,
Foreground = Resources["SystemControlForegroundBaseHighBrush"] as Brush,
VerticalAlignment = VerticalAlignment.Top,
IsHitTestVisible = false,
Text = "Jerry Nixon",
};
_paneTitleTextBlock.SetValue(Grid.ColumnProperty, 1);
_paneTitleTextBlock.SetValue(Grid.RowProperty, 1);
_paneTitleTextBlock.SetValue(Canvas.ZIndexProperty, 100);
// parent_grid.Children.Add(_paneTitleTextBlock);
_backButton = new Button
{
Name = "BackButton",
Content = new SymbolIcon
{
Symbol = Symbol.Back,
IsHitTestVisible = false
},
Style = Resources["PaneToggleButtonStyle"] as Style,
};
_backButton.SetValue(Canvas.ZIndexProperty, 100);
parent_grid.Children.Insert(1, _backButton);
NavigationService.CanGoBackChanged += (s, args) =>
{
_backButton.IsEnabled = NavigationService.CanGoBack();
};
_backButton.Click += (s, args) =>
{
var gesture_service = GestureService.GetForCurrentView();
gesture_service.RaiseBackRequested();
};
}