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Can I make a ContentDialog.Async() await another ContentDialog.Async() in UWP?

I'm running an UWP app with 2 pages. In MainPage I start a ContentDialog Async method which opens page2 in a frame. In page2 I have a secondary ContentDialog which I open by pressing a button.
In the Button_Click method I want to close the running Async() method and await to start the next one until I am 100% sure the first one is closed.
The problem I encounter now is that the program crashes if I press the secondary ContentDialog's buttons too fast after it opens.
I've tried thread sleeping but that only delays the problem.
Mainpage(CustomerInfoPage):
transactionContent = new ContentDialog();
Frame transactionFrame = new Frame();
transactionFrame.Navigate(typeof(TransactionPage), selectedAccount);
transactionContent.Content = transactionFrame;
transactionContent.ShowAsync();
Page2(TransactionPage):
private async void DepositButton_ClickAsync(object sender, RoutedEventArgs e)
{
CustomerInfoPage.transactionContent.Hide();
ContentDialog confirmationDialog = new ContentDialog
{
Title = "Deposit Funds.",
Content = $"You will deposit {depositTextBox.Text} SEK.\nYour new balance will be: {ReceivedAccount.Balance + deposit} SEK",
PrimaryButtonText = "CONFIRM",
SecondaryButtonText = "CANCEL"
};
confirmationDialog.PrimaryButtonClick += ConfirmationDialog_PrimaryButtonClick;
await confirmationDialog.ShowAsync();
async void ConfirmationDialog_PrimaryButtonClick(ContentDialog _sender, ContentDialogButtonClickEventArgs args)
{
confirmationDialog.Hide();
}
CustomerInfoPage.transactionContent.ShowAsync();
}
So this works as long as you don't call the ConfirmationDialog_PrimaryButtonClick too fast by clicking on it instantly after it is opened.

This is introduced in the UWP documentation about Dialog.
There can only be one ContentDialog open per thread at a time. Attempting to open two ContentDialogs will throw an exception, even if they are attempting to open in separate AppWindows.
So you can't start the second CotnentDialog while the first ContentDialog is still running.
Best regards.

As #Richard Zhang - MSFT said in previous answer
So you can't start the second CotnentDialog while the first
ContentDialog is still running.
If you wish to close the ContentDialog from previous page right before opening new ContentDialog you can use the code from below which will close any ContentDialog which is currently open.
var openedpopups = VisualTreeHelper.GetOpenPopups(Window.Current);
foreach (var popup in openedpopups)
{
if(popup.Child is ContentDialog)
{
(popup.Child as ContentDialog).hide();
}
}

Why incorrect order of navigation from SplashScreen to MainPage

I trying to understand an example app by Microsoft. Now I can't repeat the next part. The app have classes App and ExtendedSplach. I want to repeat loading by ExtendedSplash. In my case, it's simple switch from splash to main page after some delay.
Introduction
The example to do like this.
If app runs with breakpoints on line .Content = extendedSplash and .Content = rootFrame, then the first will be extendedSplash. But line .Content = extendedSplash the follow after .Content = rootFrame. The constructor ExtendedSplash calls LoadDataAsync that set .Content = rootFram by first.
However, method LoadDataAsync contains await call
await Startup.ConfigureAsync();
I think that thus the first will extendedSplash. And we will see loading page.
class App
...
bool loadState = (e.PreviousExecutionState == ApplicationExecutionState.Terminated);
ExtendedSplash extendedSplash = new ExtendedSplash(e, loadState);
Window.Current.Content = extendedSplash;
Window.Current.Activate();
class ExtendedSplash
public ExtendedSplash(IActivatedEventArgs e, bool loadState)
{
...
LoadDataAsync(this.activatedEventArgs);
}
private async void LoadDataAsync(IActivatedEventArgs e)
{
...
rootFrame.Navigate(typeof(LoginView), shellArgs);
Window.Current.Content = rootFrame;
Window.Current.Activate();
}
Problem
I tried to repeat the same. I want see loading and then swith to other page. But my case with breakpoints looks like the first .Content = rootFrame and the second .Content = extendedSplash. Thus my queue are logo app with delay 5 seconds and then page with extendedSplash. The page rootFrame losing.
I will grateful for any help.
My code
I did the same by App class
bool loadState = (e.PreviousExecutionState == ApplicationExecutionState.Terminated);
ExtendedSplash extendedSplash = new ExtendedSplash(e, loadState);
Window.Current.Content = extendedSplash;
Window.Current.Activate();
And the next by ExtendedSplash
public ExtendedSplash(IActivatedEventArgs e, bool loadState)
{
this.InitializeComponent();
Window.Current.SizeChanged += new WindowSizeChangedEventHandler(ExtendedSplash_OnResize);
this.splashScreen = e.SplashScreen;
this.activatedEventArgs = e;
OnResize();
rootFrame = new Frame();
LoadDataAsync(activatedEventArgs);
}
private async void LoadDataAsync(IActivatedEventArgs e)
{
await Test();
rootFrame.Navigate(typeof(MainPage));
Window.Current.Content = rootFrame;
Window.Current.Activate();
}
private async Task Test()
{
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
while (stopwatch.ElapsedMilliseconds < 5000) ;
}

The problem with your code is in fact in the Test() method. You have marked is async, but that doesn't make the method asynchronous. Instead, your code will actually be stuck for five seconds in blocking manner in the while loop.
Try the following version:
private async Task Test()
{
await Task.Delay(5000);
}
This form of code is in fact asynchronous, so as a result the UI thread will be free to display the splash screen in the meantime.
In general - async methods run on the thread that calls them until they hit an "actual" asynchronous code - for example I/O bound async method or when you run your code with await Task.Run(()=>{...}.

How to close secondary view in uwp

I'm building an UWP app that spawn second view besides the main view.
I want to close the second view from the main view.
I already try to google it, but most of it only show me how to spawn but not to close.
Below is the code block I use to open a new view, and at its bottom is how I try to close the newly created view that always ends up fail.
public async void OpenNew(Type type, string title, string uniqueId)
{
CoreApplicationView newView = null;
if (!IsExists(uniqueId))
{
newView = CoreApplication.CreateNewView();
int newViewId = 0;
await newView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
Frame frame = new Frame();
Window.Current.Content = frame;
Window.Current.Activate();
frame.Navigate(type);
newViewId = ApplicationView.GetForCurrentView().Id;
ApplicationView.GetForCurrentView().Title = title;
ApplicationView.GetForCurrentView().Consolidated += OnConsolidated;
});
await ApplicationViewSwitcher.TryShowAsStandaloneAsync(newViewId);
_uniqueIds.Add(uniqueId, newViewId);
}
// Below code testing on how I try to close newly spawned view but always throw error
await Task.Delay(5000).ContinueWith(async _ =>
{
await Window.Current.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
newView.CoreWindow.Close();
});
});
}
This code always throws
Exception thrown: 'System.NullReferenceException'
Any link or tutorial on how to do it?

Nvm, guys I got the answer. Below is my changes on the part where I try to close the 2nd view from the above code:
await Task.Delay(5000).ContinueWith(async _ =>
{
await newView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
CoreWindow.GetForCurrentThread().Close();
});
});

UWP Custom Constructor when creating a secondary window

I'm developing a quick application with the sole purpose of using picture-in-picture mode (compact view) in UWP to display Youtube videos over top of my work. Here's the way the current system works:
MainPage - Handles searching of youtube videos
YoutubeItem - A usercontrol that the mainpage creates for each youtube result. Approximately 50 of these are put into a wrap panel.
YoutubeViewer - A seperate page that runs in it's own window and displays the youtube video.
Here's my issue. I store all the information for the youtube video in each of the YoutubeItems. Using a button, I record the click event and handle it. Here's the code for handling the click:
private async void Button_Click(object sender, RoutedEventArgs e)
{
CoreApplicationView newView = CoreApplication.CreateNewView();
int newViewId = 0;
await newView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
Frame frame = new Frame();
frame.Navigate(typeof(YoutubeViewer), null);
Window.Current.Content = frame;
// You have to activate the window in order to show it later.
Window.Current.Activate();
newViewId = ApplicationView.GetForCurrentView().Id;
});
bool viewShown = await ApplicationViewSwitcher.TryShowAsStandaloneAsync(newViewId);
}
The problem arises when I have to send the link for the video to the YoutubeViewer. Originally, I was doing this through a constructor but upon using this method for the Windows Documentation, I am unable to use my own constructor from my knowledge. How would you folks recommend getting the link to the new window?

There are many ways.
the simplest, though not necessarily the most elegant, is to create a new class that inherits from Frameand add to it a property for the link. Something like this:
public class FooFrame: Frame
{
public string Link;
}
then in your code assign it upon initializing the frame:
FooFrame frame = new FooFrame(){Link = "youtube.link.com"}

UWP C# pass a variable to another thread

Im new to programming, and after 7 days of searching I couldn't find a solution.
My "MainPage" opens, and I click to Open a "SecondaryPage" which opens on a new thread window with core Dispatcher. My "MainPage" has a button Click event which updates "TextBlock1". What I cant achieve is to pass this value to my "SecondPage" "TextBlock2".
MainPage.xaml below.
<StackPanel>
<Button Click="Button_Click_NewWindow" Content="Start a new window" FontSize="30"/>
<TextBlock Name="Textblock1" Text="Empty" FontSize="30"/>
<Button Click="Button_Click_Add" Content="+1" FontSize="30"/>
</StackPanel>
Code Behind SecondPage.xaml
<StackPanel>
<TextBlock Name="Textblock2" Text="Empty" FontSize="30"/>
</StackPanel>
MainPage.xaml.cs
namespace MulitViewV1
{
public sealed partial class MainPage : Page
{
public int T1G = 0;
public MainPage()
{
this.InitializeComponent();
}
private async void Button_Click_NewWindow(object sender, RoutedEventArgs e)
{
CoreApplicationView newView = CoreApplication.CreateNewView();
int newViewId = 0;
await newView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
Frame frame = new Frame();
frame.Navigate(typeof(SecondPage), null);
Window.Current.Content = frame;
// You have to activate the window in order to show it later.
Window.Current.Activate();
newViewId = ApplicationView.GetForCurrentView().Id;
});
bool viewShown = await ApplicationViewSwitcher.TryShowAsStandaloneAsync(newViewId);
}
private async void Button_Click_Add(object sender, RoutedEventArgs e)
{
T1G = T1G + 1;
Textblock1.Text = T1G.ToString();
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
//UI code here
// NOT WORKING error "TextBlock2" does not exist in the current context
Textblock2.Text = T1G.ToString();
});
}
}
}
I see the Dispatcher is working to my MainPage View, but I cant figure out code to direct it to my SecondPage "newViewID".

There's no need to call Dispatcher all the time. You button clicks are coming to you on the UI thread so the handlers are also going to be on the UI thread.
A way to think about it is that you're always on the UI thread unless you're doing something with *Async. If you await async stuff, you're good. This is not true all of the time, but it's a place to start and handle the problems you might encounter as the come.
Generally you only want a single Frame in your application. Multiple Frames (and multiple windows) is an advanced topic; save it for later.
By default, you UWP app will contain a Frame. Pages are hosted in this frame. The frame can navigate between the pages it hosts. Think of the frame as you browser window, and the pages are like web pages.
You can get the Frame by getting the Frame property on the page. To navigate to a new page you do this:
private async void Button_Click_NewWindow(object sender, RoutedEventArgs e)
{
Frame.Navigate(typeof(SecondPage), null);
}
Next you want to change the text of TextBlock2. TextBlock2 is located on SecondPage, but your code is in MainPage, which has no TextBlock2, and the compiler is telling you that TextBlock2 isn't a thing in MainPage.
Inside your SecondPage.xaml.cs you are however able to get to TextBlock2 as it is present there. Remember though, MainPage will not be visible after navigation to SecondPage (just as you can't see two web pages at the same time when navigating from one to another).

In your Button_Click_NewWindow where you are calling
frame.Navigate(typeof(SecondPage), null);
instead of null, pass the text from TextBlock like below
string TextBoxText = Textblock1.Text;
frame.Navigate(typeof(SecondPage), TextBoxText);
And in your SecondPage, Override OnNavigated to method and you can get the Text like below.
string PassedText=e.parameter.ToString();
and you can assign this to your TextBlock as below
Textblock2.Text=PassedText;
Update
Change your Button_Click_NewWindow to below and add the two variables on top.
int newViewId = 0;
Window SecondWindow;
private async void Button_Click_NewWindow(object sender, TappedRoutedEventArgs e)
{
string TextBoxText = Textblock1.Text;
int mainViewId = ApplicationView.GetApplicationViewIdForWindow(CoreApplication.MainView.CoreWindow);
if (newViewId == 0)
{
CoreApplicationView newCoreView = CoreApplication.CreateNewView();
ApplicationView newAppView = null;
await newCoreView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
newAppView = ApplicationView.GetForCurrentView();
Window.Current.Content = new Frame();
(Window.Current.Content as Frame).Navigate(typeof(SecondPage), TextBoxText);
Window.Current.Activate();
SecondWindow = Window.Current;
});
newViewId = newAppView.Id;
}
else
{
await SecondWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
SecondWindow.Content = new Frame();
(SecondWindow.Content as Frame).Navigate(typeof(SecondPage), TextBoxText);
SecondWindow.Activate();
});
}
await ApplicationViewSwitcher.TryShowAsStandaloneAsync(newViewId, ViewSizePreference.UseHalf, mainViewId, ViewSizePreference.UseHalf);
}
And your output