Duplicate Page Items Error after Upgrading to Version 1.0 Experimental

[ghost1372]

Describe the bug
After Upgrading to Version 1.0 Experimental I get the following error

Error NETSDK1022 Duplicate 'Page' items were included. The .NET SDK includes 'Page' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultPageItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The duplicate items were: 'MainWindow.xaml' App21 C:\Users\Mahdi\.nuget\packages\microsoft.projectreunion.winui\0.8.0\buildTransitive\Microsoft.WinUI.targets 54

Steps to reproduce the bug

Steps to reproduce the behavior:

1. Create a new WinUI 3 Packaged Project
2. Install a Nuget Package for example (<PackageReference Include="CommunityToolkit.WinUI.UI.Controls" Version="7.0.3" />)
3. Compile Project

Expected behavior
Project Should be Compiled without problem

Screenshots

Version Info

NuGet package version:

Windows 10 version	Saw the problem?
Insider Build (xxxxx)
May 2020 Update (19041)	Yes
November 2019 Update (18363)
May 2019 Update (18362)
October 2018 Update (17763)

Additional context

note that The problem arises when a nuget package is installed (i tested in VS 2019 preview and VS 2022 preview)

[ghost1372]

I think this is because nuget packages are based on
Microsoft.ProjectReunion " Version="0.8.0"
And in the experimental version, these packages have been renamed to
Microsoft.WindowsAppSDK
So is there a solution to using these nuget packages? Or should we wait for them to update?
Can a Visual Studio update solve this problem? If yes, it is better to report this problem to the VS team as soon as possible

[andrewleader]

Thanks for filing this @ghost1372. I think you'll need to wait for the NuGet packages you're using to update to the new WindowsAppSDK NuGet package. This is definitely a pain, but this rename was coming regardless and would be painful no matter what, so that's why we're trying to start early to give everyone time to update to the new package!

We'll work with our ecosystem partners to try to get these other libraries updated!

[JanRajnoha]

@ghost1372 Could you please report bug into Community toolkit?

[ghost1372]

@JanRajnoha Done

[MarkBrainfire]

After updating to Microsoft.WindowsAppSDK (1.0.0-experimental1) I get the same "Duplicate 'Page' items ..." error IF AND ONLY IF I also install Syncfusion.Grid.WinUI Nuget package (19.2.0.62) which has a dependency on Microsoft.ProjectReunion (0.8.1).

[andrewleader]

@MikeHillberg do you think this is XAML related (duplicate 'Page' items)? If we have this problem every time we rev a new version, it seems like having community libraries will be unfeasible since community libraries definitely aren't going to keep up-to-date with the latest library.

[capegreg]

This is not only with Experimental version. I am using Project Reunion 0.8.4.5305616. I created a new C# App (WinUI 3 in Desktop) project with Windows Template Studio. The installed packages include:

• CommunityToolkit.Mvvm 7.0.3
• CommunityToolkit.WinUI.UI.Controls.DataGrid 7.0.3
• Microsoft.Extensions.DependencyInjection 5.0.2
• Microsoft.ProjectReunion (originally 0.8.0, updated to 0.8.5 -- no issues up to here)
• Microsoft.Xaml.Behaviors.WinUI.Managed (originally 2.0.4, duplicate 'Page' items error received once this was updated to 2.0.5, no change with 2.0.6)

[JanRajnoha]

@capegreg if you look better at dependencies with Microsoft.Xaml.Beahaviors.WinUI.Managed, so you will notice version 2.0.5 is using Win App SDK 1.0 exp1 and version 2.0.6 is using experiment 2, so if you will upgrade to 2.0.5, you will install Windows App SDK 1.0 too

[capegreg]

@JanRajnoha Ah, yes. thank you for pointing that out. Do you see any reason why I should not be able to hold at 2.0.4 and proceed with my development, then update again in the future?

[JanRajnoha]

@capegreg I'm currently using 2.0.4 and don't see ane reason to upgrade... For now, but with winui 1.0 I want to upgrade, but current working version is okay

[ghost1372]

WCT 7.1.1-preview3 released based on WASDK 1.0.0-preview3