The tag 'XamlControlsResources' does not exist in XML namespace 'using:Microsoft.UI.Xaml.Controls'

Question

I was trying to use WinUI so I installed the plugin Microsoft.UI.Xaml (2.4.2) from Nuget and followed the instructions which says add This <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls"/> to my App.Xaml

and here is my App.Xaml file

<Application x:Class="WpfApp1.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WpfApp1"
    StartupUri="MainWindow.xaml">
        <Application.Resources>
            <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
        </Application.Resources>
</Application>

but it says:

The tag 'XamlControlsResources' does not exist in XML namespace 'using:Microsoft.UI.Xaml.Controls'

i tried older versions from WinUI plugin and tried .Net Core and Framework but still having this problem

Expansile

In my case, I installed a WPF library that causes this exception. After removing that library, my application works fine. – Grasping

Answer 1

I believe this WinUI 2.4.2 library is only compatible if you create a UWP application, not a WPF app.

Having said that, according to this documentation from Microsoft, starting with WinUI 3, you will be able to do this in WPF.

Theomania

yea you are right, i was going to delete my question after reading those documents but found out that you answered me already so i accepted the question and im gonna keep it, thanks for the answer :) – Expansile

Answer 2

Add

<package id="Microsoft.UI.Xaml" version="2.5.0-prerelease.200812001" targetFramework="native" />

If you browse and can't find it add a line containing the above to the packages.config file check installed and the wait for Restore to show up in Nuget tools.

Make certain a reference is in the <Import Project="packages\Microsoft.UI.Xaml" version="2.5.0-prerelease.200812001..."

And also the <Error Condition="!Exists('packages\Microsoft.UI.Xaml" version="2.5.0-prerelease.200812001..." in the .vcxproj file for your project.

Peppy

actually i was supposed to use UWP but i didnt know that at first, i was using WPF thats why it wasn't working, but thanks anyways – Expansile