ApplicationBar not working after navigation Windows 8 - windows-8

I am developing simple app on Windows 8.
I have two UserControls: Locations and LocationsMap.
I am trying to navigate between them. For that I have added to static methods into App. They are like this
public static void ShowLocationsMap()
{
var page = new LocationsMap();
Window.Current.Content = page;
}
Navigation works fine.
But there is a problem. I am calling this method from button in ApplicationBar. XAML looks like this
<ApplicationBar x:Name="BottomAppBar" Height="88" VerticalAlignment="Bottom" Style="{StaticResource AppBarStyle}" Grid.Row="1">
<StackPanel Orientation="Horizontal">
<!-- Margin="left,top,right,bottom" -->
<StackPanel Orientation="Vertical" Margin="5,14,5,14">
<Button Content="Map" Click="MapButton_Click"></Button>
</StackPanel>
</StackPanel>
</ApplicationBar>
And I am navigating back by calling other function from next page.
The problem is that when I navigates back, ApplicationBar stopping to work. It is not showing after right click. If I set BottomAppBar.IsOpen to true, it shows up, but didn't closing.
Where is the problem?
P.S.
ApplicationBar is not working as well in case when I am navigating to other page from button on controls XAML, so problem is not on button inside AppBar.

For navigation I was using sample code downloaded from internet. That code was using static functions defined in App class, which were changing Window.Current.Content.
That was bad idea. Instead if that I just need to use Frame navigation.
When using it we need to change type of our controls from UserControl to Page.
Application bar works great with navigation now.
Hope this will help someone.

Related

uwp NavigationView control Titlebar

I have a problem with the NavigationView Control and the titlebar.
I have tried to extend the view into the titlebar to play with the acrylic effects of the standard NavigationView. But then I´ve noticed that the back and menu buttons are underneath the titlebar, so you´re not able to click them properly.
In the attached image, you can see that everything under the red line is clickable but when you go over it, you are targeting the titlebar.
Is there anything I can do to fix this behavior?
I don't know which version OS you are working on, I didn't see this problem in recent Windows insider OS.
You may workaround the not clickable problem by set a dummy Titlebar like below:
<Grid>
<Grid x:Name="AppTitleBar" Background="Transparent" />
<NavigationView IsBackEnabled="True" PaneDisplayMode="Top">
<NavigationView.MenuItems>
<NavigationViewItem Icon="Accept" Content="Accept" />
</NavigationView.MenuItems>
</NavigationView>
</Grid>
public MainPage()
{
this.InitializeComponent();
var coreTitleBar = CoreApplication.GetCurrentView().TitleBar;
coreTitleBar.ExtendViewIntoTitleBar = true;
Window.Current.SetTitleBar(AppTitleBar);
}

How to call another page using Tap Gesture in Xamarin.Forms?

I created an Image Button and put a Tap Gesture into it. I want my Image Button to call another Page but I don't know how am I going to do that without using Navigation.PushAsync but it's causing me this error "PushAsync is not supported globally on Android, please use a Navigation Page."
This is my XAML code.
<Image Source="add.jpg">
<Image.GestureRecognizers>
<TapGestureRecognizer
Tapped="TapGestureRecognizer_OnTapped"
NumberOfTapsRequired="1" />
</Image.GestureRecognizers>
</Image>
and this is my XAML.CS code.
private void TapGestureRecognizer_OnTapped(SecondPage secondPage)
{
Navigation.PushAsync(new SecondPage());
}
If you need to use PushAsync, the parent Page should be a NavigationPage.When we use NavigationPage and do PushAsync the Navigation stack will be maintained and you will get a back button in Actionbar for back navigation.
Rather if we use PushModalAsync, the page will be presented modally.
Changing PushAsync to PushModalAsync will work.
private void TapGestureRecognizer_OnTapped(SecondPage secondPage)
{
Navigation. PushModalAsync(new SecondPage());
}

What prevents a Navigation between two XAML-pages?

I am experiencing a very strange bug in my c++/cx XAML app:
I have a back-button that checks if the progress you made is saved and (in case it isn't) pops up a flyout that lets you save or leave without saving. This is done with this->frame->goBack() in both cases, however:
When the progress was saved, the app halts at a __debugbreak() however, when goBack() is called by the button on the flyout, everything works out fine. Why could that possibly be the case?
Things that might help you:
The app is based on the "Blank App" template, the pages itself are based on the "Basic Page" template provided by Visual Studio 2013
The Controls in BoardPage.xaml are defined as follows:
<AppBarButton x:Name="backButton" Icon="Back" Height="95"
Click="backButton_Clicked">
<AppBarButton.Resources>
<Flyout x:Key="WarningFlyoutBase">
<Grid Height="150" Width="200">
<Grid.RowDefinitions>
<RowDefinition Height="1*"/>
<RowDefinition Height="1*"/>
<RowDefinition Height="1*"/>
</Grid.RowDefinitions>
<TextBlock Text="Unsaved progress, what do you want to do?"
HorizontalAlignment="Center" TextWrapping="Wrap"
FontSize="14" Margin="4,10" TextAlignment="Center"/>
<Button x:Name="WarningSaveButton"
Content="Save now."
Grid.Row="1" HorizontalAlignment="Center"
Click="WarningSaveButton_Clicked"/>
<Button x:Name="WarningLeaveButton"
Content="Leave without saving."
Grid.Row="2" HorizontalAlignment="Center"
Click="WarningLeaveButton_Clicked"/>
</Grid>
</Flyout>
</AppBarButton.Resources>
<AppBarButton.Flyout>
<StaticResource ResourceKey="WarningFlyoutBase"/>
</AppBarButton.Flyout>
</AppBarButton>
so these three controls (backButton, WarningSaveButton and WarningLeaveButton) all have their respective Clicked event handlers, though only two of them are relevant right now:
backButton:
void Tackle::BoardPage::backButton_Clicked(Platform::Object^ sender,
Windows::UI::Xaml::RoutedEventArgs^ e)
{
if (saved && Frame->CanGoBack) /* saved is a bool */
this->Frame->GoBack();
else
backButton->Flyout->ShowAt((FrameworkElement^)sender);
}
Note: I also tried replacing GoBack() with Navigate(TypeName(CreateGamePage::typeid)), but that didn't help.
WarningLeaveButton:
void Tackle::BoardPage::WarningLeaveButton_Clicked(Platform::Object^ sender,
Windows::UI::Xaml::RoutedEventArgs^ e)
{
if (Frame->CanGoBack)
this->Frame->GoBack();
}
other strange stuff:
I tried to examine the reasons for this crash/debugbreak for quite some time, and found the following:
the page in question is navigated to with this->Frame->Navigate(TypeName(BoardPage::typeid), ref new CGameSession(job));. leaving out the second argument fixes the crash magically.
When the breakpoint is triggered in App.g.hpp, opening a watch on the value errorMessage reveales:
"Placement target needs to be in visual tree."
How come the Flyout is in the visual tree, but the Button it's been attached to isn't?
The target page is in fact constructed, but the NavigationHelper->OnNavigatedTo(e) method fails in the last line LoadState(this, ref new LoadStateEventArgs(e->Parameter, safe_cast<IMap<String^, Object^>^>(frameState->Lookup(_pageKey))));, wich seems paritularly odd, because LoadState() gets called easily and only contains two (void) typecasts. (I have not modified a single one of these methods.)
The Problem here lies within the way flyouts and event handlers work with XAML-Controls, there are 2 mayor points that cause my code to crash:
Flyouts are always shown when the button they're attached to is clicked or tapped.
Event Handlers seem to be executed before the flyout gets shown.
What follows from this?
Well, when the backButton is pressed, backButton_Clicked gets triggered first.
When the game is not saved, the flyout opens and you can go back without a Problem.
But if the game was saved previously, the event handler immediately calls this->Frame->GoBack(), wich does exactly what it should, constructs the previous page, loads its state and draws it.
BUT after that, it tries to open the flyout, and this is the problem here: The flyout doesn't exist anymore, hence the strange error Message.
I am kind of embarassed it took me this long to figure it out, but maybe someone will find this useful in the future, so I'm going to leave this question here.
Workaround:
The workaround I'm using for this now is to move the FlyoutBase to the <Page.Resources> and attach it to a button with a size of 0x0 px. Triggering the flyout then done like so: Flyout::ShowAttachedFlyout(InvisibleButton);

Start An Event After Scrolling

I'm new to Windows Phone apps development, and I've created a scrolling menu using the following xaml code :
<ScrollViewer HorizontalAlignment="Left" Margin="18,0,0,0" Name="scrollViewer1" VerticalAlignment="Top" Width="450" HorizontalScrollBarVisibility="Auto" Grid.Row="1">
<StackPanel Height="Auto" Name="stackPanel1" Width="Auto">
<Button Height="620" FontSize="120" Name="gotoGmail" Width="Auto">Gmail</Button>
<Button Height="620" FontSize="120" Name="gotoYahoo" Width="Auto">Yahoo</Button>
</StackPanel>
</ScrollViewer>
I'd like to know whether it's possible to start an event once the user scrolls the menu from one button to another. If it is possible, i'd be grateful if you could explain how. If it's not , i'd like to hear about how could I do it using different tools rather than ScrollViewer. Thanks in advance !
There's no "Scrolled" event on the ScrollViewer, but what you can do is two-way bind a property to VerticalOffset. That lets you trigger an event/command from your view/viewmodel when the scroll changes.
Something like this:
<ScrollViewer VerticalOffset="{Binding VerticalOffset,Mode=TwoWay}" ...
And then in the data context:
public double VerticalOffset
{
get { return _verticalOffset; }
set
{
_verticalOffset = value;
// call "on scroll changed" actions here
}
}
private double _verticalOffset = 0;
how could I do it using different tools rather than ScrollViewer
You can of course make a scrolling menu using other approaches. I'll bet there is some nifty approach you could figure, using the WinRT transitions/animations stuff, but I'm not familiar enough with those to say. Here are some others (not sure which would be best/easiest for your scenario):
Probably using Canvas would be a quick-and-dirty way to do it (just set up buttons that set off Canvas.Left and Canvas.Top animations).
Extending ItemsControl along with a custom ControlTemplate would be a good approach if you want to create a re-usable component.
I like extending Panel, but you have to do the animations manually using a DispatcherTimer, and you have to lay out the buttons yourself using Measure and Arrange.

Navigate to the last frame from SwapChainBackgroundPanel

I am writing a Windows Store app using C++/XAML with DirectX interop - SwapChainBackgroundPanel.
The application is based on the template "Split Page". From each list view item, a DirectX page may be launched using code below.
Window::Current->Content = ref new MyD3Components::DirectXPage();
Window::Current->Activate();
This is working fine and DirectX page opens up and plays very well.
What I would like to have a button in the app bar which helps user to go back and display the "Split Page" to allow selecting another DirectX page. This I have not been able to accomplish yet.
Among several things I have tried, below is the most logical one to my opinion. It gives a "Platform::DisconnectedException" when user wants to go back to the last page.
Windows::UI::Xaml::Controls::Frame^ rootFrame = SDL::App::GetRootFrame();
Window::Current->Content = rootFrame;
Window::Current->Activate();
Please look to see if you have a suggestion or better a solution.
Here the sample example for your question :
What i am creating : 2 pages...
You will have (go to page 2)link on page 1...If u click that,the second page should appear that says "Page 2" at the top. Notice that there is a back button to the left of the page title. Click the button to return to the first page...
1.) Find the TextBlock element named pageTitle and change the Text property to Page 1. The XAML should look like this:
<TextBlock x:Name="pageTitle" Grid.Column="1" Text="Page 1"
Style="{StaticResource PageHeaderTextStyle}"/>
2.)Add the following XAML as a second child element to the root Grid. The StackPanel element should be a sibling to the Grid that contains the back button and page title.
<StackPanel Grid.Row="1"
Margin="120,0,120,60">
<HyperlinkButton Content="Click to go to page 2" Click="HyperlinkButton_Click_1"/>
</StackPanel>
3.)Make the following changes to BasicPage2.xaml.
Find the TextBlock element named pageTitle and change the Text property to Page 2. The XAML should look like this:
<TextBlock x:Name="pageTitle" Grid.Column="1" Text="Page 2"
Style="{StaticResource PageHeaderTextStyle}"/>
4.)Add the following XAML as a second child element to the root Grid. The StackPanel element should be a sibling to the Grid that contains the back button and page title.
<StackPanel Grid.Row="1"
Margin="120,0,120,60">
<TextBlock HorizontalAlignment="Left" Name="tb1" Text="Hello World!"/>
</StackPanel>
5.)Add the following code to the BasicPage1 class in BasicPage1.Xaml.cs
private void HyperlinkButton_Click_1(object sender, RoutedEventArgs e)
{
this.Frame.Navigate(typeof(BasicPage2));
}
6.)Now that we've prepared the new pages, we need to make BasicPage1 the first thing that appears when the app starts. Open app.xaml.cs and change the OnLaunched method to call Frame.Navigate by using BasicPage1 instead of the BlankPage. The entire OnLaunched method should look like the following:
protected override void OnLaunched(LaunchActivatedEventArgs args)
{
// Create a Frame to act navigation context and navigate to the first page
var rootFrame = new Frame();
rootFrame.Navigate(typeof(BasicPage1));
// Place the frame in the current window and ensure that it is active
Window.Current.Content = rootFrame;
Window.Current.Activate();
}
Now you are ready to test the app. Start the app, and click the link that says Click to go to page 2. The second page should appear that says "Page 2" at the top. Notice that there is a back button to the left of the page title. Click the button to return to the first page.
Thats it! hope it helps u.
After a bit of trial and error, I am in the position to answer my own question. It seems that all I needed to do was to remove my rendering callbackfrom the CompositionTarget.
It was added like below.
m_eventToken = CompositionTarget::Rendering::add(ref new Windows::Foundation::EventHandler<Object^>(this, &DirectXPage::OnRendering));
Before replacing the current window and activating it, I called below.
CompositionTarget::Rendering::remove(m_eventToken);
I guessed this helped DirectX not to output to rendering pipeline and complain (disconnectedexception) when the target is not there.