[BUG] mct:EventToCommandBehavior not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

[jamesv-7]

Is there an existing issue for this?

• I have searched the existing issues

Did you read the "Reporting a bug" section on Contributing file?

• I have read the "Reporting a bug" section on Contributing file: https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md#reporting-a-bug

Current Behavior

I am using your Samples project from this GitHub repo because I was having issues with every version of MauiComminutyToolkit since 9.0.3

When I run your sample project i get the following error when I click on any of the following Behaviors. I did not test them all. But these are not working.

Position 25:18. Type mct:EventToCommandBehavior not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

AnimationBehavior
EventToCommandBehavior
MaskedBehavior

In my personal project I'm getting the following error

Type toolkit:StatusBarBehavior not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
Type toolkit:TextCaseConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
Type toolkit:InvertedBoolConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
Type toolkit:EventToCommandBehavior not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
Type toolkit:IntToBoolConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
Type toolkit:IconTintColorBehavior not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

here is my global.json file

{
"sdk": {
"version": "9.0.101",
"rollForward": "latestFeature",
"allowPrerelease": false
}
}

Expected Behavior

I would expect the behaviors and converters to reference correctly.

Steps To Reproduce

1. Run your samples project from this GitHub repo - i added it below as well
2. Click on the Flyout
3. Select Behaviors
4. Click EventToCommandBehavior

Link to public reproduction project repository

https://github.com/jamesv-7/CommunityToolkit-10.0-Issues

Environment

- .NET MAUI CommunityToolkit:
- OS: MAC Sequoia 15.1
- .NET MAUI: 9.0
- XCode 16.1

Anything else?

No response

[TheCodeTraveler]

@jamesingreersc Your issue is not related. Here's the relevant excerpt from the Release Notes to fix your issue:

[jamesingreersc]

@brminnick ahhh, release notes :) Thats what I get for updating all nugets at once without reading them. Just tested with the new BindingContext and it's working just fine.

[gmwilhelm]

Do i also have to set the binding context for converters? Or is the breaking change only for behaviors?

The release notes only mention behaviors, but i get the error

Type toolkit:IsNotNullConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

[TiberiusDRAIG]

Do i also have to set the binding context for converters? Or is the breaking change only for behaviors?

The release notes only mention behaviors, but i get the error

Type toolkit:IsNotNullConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

@brminnick We're having the same problem here with .NET 8.0.404 with all the MCT converters in debug builds on MacOS, but absolutely fine on Windows. Seems to build fine for MacOS on DevOps in Release with the same SDK and workloads.

EDIT: This is with latest 9.x MCT for .NET 8

EDIT2: Seems to be related to linking - if set to 'Link Framework SDKs Only', as our debug project is, we get this error. Disabling linking makes MCT work, but then breaks other stuff in the build. Possibly something changed in the SDK? We were previously using 8.0.101 on MacOS 14.x where this worked, but with 8.0.404 on MacOS 15.x it now fails.

EDIT3: Excluding MCT from trimming resolves the issue (FYI @gmwilhelm & @jamesv-7) - add the following to your csproj then make sure to clear your bin and obj folders:

<ItemGroup>
    <TrimmerRootAssembly Include="CommunityToolkit.Maui"/>
</ItemGroup>

[ojuniour]

I'm getting thewsamw issue with "EnumToBoolConverter":

        <ResourceDictionary>
            <toolkit:EnumToBoolConverter x:Key="enumToBoolConverter"  />
        </ResourceDictionary>

{Microsoft.Maui.Controls.Xaml.XamlParseException: Position 15:14. Type toolkit:EnumToBoolConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit
   at Microsoft.Maui.Controls.Xaml.CreateValuesVisitor.Visit(ElementNode node, INode parentNode)
   at Microsoft.Maui.Controls.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
   at Microsoft.Maui.Controls.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
   at Microsoft.Maui.Controls.Xaml.ListNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
   at Microsoft.Maui.Controls.Xaml.RootNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
   at Microsoft.Maui.Controls.Xaml.XamlLoader.Visit(RootNode rootnode, HydrationContext visitorContext, Boolean useDesignProperties)
   at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, String xaml, Assembly rootAssembly, Boolean useDesignProperties)
   at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, String xaml, Boolean useDesignProperties)
   at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, Type callingType)
   at Microsoft.Maui.Controls.Xaml.Extensions.LoadFromXaml[LoginPage](LoginPage view, Type callingType)
   at HostedTime_Maui.Views.LoginPage.InitializeComponent()

Any solution?

[ojuniour]

Do i also have to set the binding context for converters? Or is the breaking change only for behaviors?
The release notes only mention behaviors, but i get the error
Type toolkit:IsNotNullConverter not found in xmlns http://schemas.microsoft.com/dotnet/2022/maui/toolkit

@brminnick We're having the same problem here with .NET 8.0.404 with all the MCT converters in debug builds on MacOS, but absolutely fine on Windows. Seems to build fine for MacOS on DevOps in Release with the same SDK and workloads.

EDIT: This is with latest 9.x MCT for .NET 8

EDIT2: Seems to be related to linking - if set to 'Link Framework SDKs Only', as our debug project is, we get this error. Disabling linking makes MCT work, but then breaks other stuff in the build. Possibly something changed in the SDK? We were previously using 8.0.101 on MacOS 14.x where this worked, but with 8.0.404 on MacOS 15.x it now fails.

EDIT3: Excluding MCT from trimming resolves the issue (FYI @gmwilhelm & @jamesv-7) - add the following to your csproj then make sure to clear your bin and obj folders:

> ```

<ItemGroup>
    <TrimmerRootAssembly Include="CommunityToolkit.Maui"/>
</ItemGroup>

This actually fixed the issue. Thanks. I'm hoping this is not a band-aide to a much bigger problem in the future. I hope the dev can look into it.

[gmwilhelm]

<ItemGroup>
    <TrimmerRootAssembly Include="CommunityToolkit.Maui"/>
</ItemGroup>

Adding this fixes the problem on ios, but now i get this when i try to build a release for android:

/usr/local/share/dotnet/packs/Microsoft.Android.Sdk.Darwin/35.0.24/targets/Microsoft.Android.Sdk.ILLink.targets(104,5): error MSB4096: The item "CommunityToolkit.Maui" in item list "TrimmerRootAssembly" does not define a value for metadata "RootMode". In order to use this metadata, either qualify it by specifying %(TrimmerRootAssembly.RootMode), or ensure that all items in this list define a value for this metadata.

[gmwilhelm]

Got it, it has to be

	<ItemGroup>
		<TrimmerRootAssembly Include="CommunityToolkit.Maui" RootMode="All" />
	</ItemGroup>