Question: Launching multiple windows

[Grinch]

I am attempting to activate another window instance but was greeted with the following error.

Exception thrown at 0x00007FFC4FAA67AC (KernelBase.dll) in UI.exe: WinRT originate error - 0x80004005 : 'WinUI: Error creating second Desktop Window on the current process. No more than one Desktop Window is allowed per process.'.
Unhandled exception at 0x00007FFBAAE94BA8 (Microsoft.ui.xaml.dll) in UI.exe: 0xC000027B: An application-internal exception has occurred (parameters: 0x000001E4DDF05A10, 0x0000000000000005).

There error is clear... but I am not able to find how to properly open a new window with WinUI 3 Desktop. If someone could provide me with the proper approach I would appreciate it.

[StephenLPeters]

@pratikone and @Austin-Lamb FYI

[Zidane]

Hitting this as well. Any idea from anyone in the community on the proper way to open additional Windows?

[aqibbanday]

Unhandled exception at 0x7A937E30 (Microsoft.ui.xaml.dll) in *.exe: 0xC000027B: An application-internal exception has occurred (parameters: 0x1799EA10, 0x00000001).

Window window = new Window();
window.Content = new TextBlock(){ Text = "Hello" };
window.Activate();

[Zidane]

@pratikone @Austin-Lamb @StephenLPeters

Any update on this?

[codendone]

The release of Project Reunion 0.5 does not support more than one Window in the process, and will throw this error on any attempt to create a second window. Obviously this is an unfortunate limitation right now, but there is a lot of remaining work to ensure multiple windows are release quality, which is why the limitation is enforced.

Preview builds, including the Project Reunion 0.5 preview from a few weeks ago and the upcoming Project Reunion 0.8 preview, can be used for multi-window development, with the caveat that you might hit known and unknown issues.

[aqibbanday]

Window window = new Window();
window.Content = new TextBlock(){ Text = "Hello" };
window.Activate();
The above code sample is from documentation of Project Reunion 0.5.

In preview is it possible to show window as a dialog like we do in WPF with window.ShowDialog(); method.

[codendone]

@aqibbanday Yes, that code works in preview builds.

[Grinch]

@codendone How does one work with preview builds specifically? I'm not seeing anything specific to using those off-hand.

[aqibbanday]

@Grinch I think you need to install preview WinUI 3 project templates.

[marb2000]

Closing the issue given it's a temporary limitation of the platform that will be solved, hopefully, for Reunion v1.

[Bonobomagno]

now v1 is out, but It is not working, so open it again please

[aqibbanday]

Check the road map

[Bonobomagno]

1.1, but in v1 preview 3 the issue is still there

[Reza-Noei]

Any update on this ?
@marb2000