windows – Cannot find namespace ‘CommunityToolkit.WinUI.Controls’ in WinUI 3 project with .NET 8

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I’m developing an application using WinUI 3 with .NET Core 8 and have installed CommunityToolkit.WinUI.Controls, but I’m encountering errors when trying to use SettingsCard in XAML. Here are the error messages I’m receiving:

Error (active) CS0234: The type or namespace name 'Controls' does not exist in the namespace 'CommunityToolkit.WinUI' (are you missing an assembly reference?)
Error XLS0429: Undefined namespace. The 'using' URI refers to a namespace 'CommunityToolkit.WinUI.Controls' that could not be found.
Error XLS0414: The type 'controls:SettingsCard' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built.

I have added the following lines to my XAML file:

xmlns:controls="using:CommunityToolkit.WinUI.Controls"
xmlns:ui="using:CommunityToolkit.WinUI"

And my XAML code looks like this:

<Page
    x:Class="Easy_Minecraft_Gui_WinUI3.SettingsPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Easy_Minecraft_Gui_WinUI3"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:controls="using:CommunityToolkit.WinUI.Controls"
    xmlns:ui="using:CommunityToolkit.WinUI"
    mc:Ignorable="d"
    Background="Transparent">
    
    <Grid>
        <StackPanel Spacing="4">
            <controls:SettingsCard x:Name="settingsCard"
                                   Description="This is a default card, with the Header, HeaderIcon, Description and Content set."
                                   Header="This is the Header"
                                   HeaderIcon="{ui:FontIcon Glyph=&#xE799;}"
                                   IsEnabled="{x:Bind IsCardEnabled, Mode=OneWay}">
                <ComboBox SelectedIndex="0">
                    <ComboBoxItem>Option 1</ComboBoxItem>
                    <ComboBoxItem>Option 2</ComboBoxItem>
                    <ComboBoxItem>Option 3</ComboBoxItem>
                </ComboBox>
            </controls:SettingsCard>
        </StackPanel>
    </Grid>
</Page>

I have checked the references and settings, but I’m still unable to resolve this issue. Has anyone encountered a similar problem, and is there any way to fix it?

Thank you!

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What I Tried:

1. Installation of CommunityToolkit.WinUI.Controls: I have installed the CommunityToolkit.WinUI.Controls package via NuGet in my project.

2. XAML Namespace Declarations: I added the appropriate namespace declarations in my XAML file to reference the controls from the toolkit:

   xmlns:controls="using:CommunityToolkit.WinUI.Controls"
   xmlns:ui="using:CommunityToolkit.WinUI"
   

3. Rebuilding the Project: After adding the references, I rebuilt the project multiple times to ensure all dependencies were correctly resolved.

4. Cleaning Solution: I cleaned the solution and then rebuilt it to eliminate any caching issues that could cause the error.

5. Checking for Updates: I ensured that both Visual Studio and the Community Toolkit were updated to their latest versions.