A class library with a ResourceDictionary will crash with AOT/Trim enabled

[ghost1372]

Describe the bug

I have a class library that contains some ResourceDictionaries which i refrence them into app.xaml

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
            <ResourceDictionary Source="ms-appx:///WinUICommunity.Components/Themes/Generic.xaml" />
            <ResourceDictionary Source="ms-appx:///WinUICommunity.LandingPages/Themes/Generic.xaml" />
            <ItemTemplates xmlns="using:WinUICommunity" />
        </ResourceDictionary.MergedDictionaries>
        <!--  Other app resources here  -->
    </ResourceDictionary>
</Application.Resources>

, When I activate the PublishAOT or Trim switch:

<PublishAOT>true</PublishAOT>
<PublishTrimmed>true</PublishTrimmed>

My app does not run in debug or release or publish mode at all.
In debug mode, I get the following exception

	Name	Value	Type
	Message	"Failed to assign to property 'Microsoft.UI.Xaml.ResourceDictionary.Source' because the type 'Windows.Foundation.String' cannot be assigned to the type 'Windows.Foundation.Uri'. [Line: 10 Position: 37]"	string
▶	Exception	{"The text associated with this error code could not be found.\r\n\r\nFailed to assign to property 'Microsoft.UI.Xaml.ResourceDictionary.Source' because the type 'Windows.Foundation.String' cannot be assigned to the type 'Windows.Foundation.Uri'. [Line: 10 Position: 37]"}	System.Exception {Microsoft.UI.Xaml.Markup.XamlParseException}

after removing my resource dictionary refrences from app.xaml My app runs without problems.

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
        </ResourceDictionary.MergedDictionaries>

    </ResourceDictionary>
</Application.Resources>

I also tried this with a new class library and an empty resource dictionary and issue exist

Steps to reproduce the bug

1.Create a New WinUI 3 Project
2.Make sure your BuildTools is 22621.3232 (latest build tools can not be launch in AOT)
3.Create a Class Library with a Resource Dictionary (Create a nuget package)
4.Add Class Library to Project
5.Add Resource Dictionary in App.xaml
6.Run app (Works fine)
7.Add <PublishAOT>true</PublishAOT> or <PublishTrimmed>true</PublishTrimmed>
8.Try to run app (app will be crash)

Expected behavior

App Should be Run/Launch without any issues

Screenshots

No response

NuGet package version

Windows App SDK 1.6.0: 1.6.240829007

Packaging type

Packaged (MSIX), Unpackaged

Windows version

Windows 11 version 22H2 (22621, 2022 Update)

IDE

Visual Studio 2022-preview, Visual Studio 2022

Additional context

No response

[ghost1372]

i found that this is related to Trim and i uploaded a Repro sample. @codendone Is there any news about fixing this bug? Actually, I can't publish any app

App1-CrashRC.zip

Open CsProj file and make sure Trim is enabled in Debug/Release

<PublishTrimmed Condition="'$(Configuration)' == 'Debug'">True</PublishTrimmed>
<PublishTrimmed Condition="'$(Configuration)' != 'Debug'">True</PublishTrimmed>

now try launch app, and you can see app will be crash.

[lhak]

I tested your repro project and it works correctly here. Make sure you use an up-to-date .net installation so that the cswinrt source generator runs.

[ghost1372]

I tested your repro project and it works correctly here. Make sure you use an up-to-date .net installation so that the cswinrt source generator runs.

Thank you.
installing CSWinRT nuget package fixed issue. i am using Visual Studio 2022 Preview.

[ghost1372]

I fixed all the crashes by installing Microsoft.Windows.CsWinRT package in the ClassLibrary project and the app itself.
so i am closing this issue