The Goal

Creating and rendering a simple WinUI3 GUI in PowerShell 7.5 which is based on .NET 9. Nothing complicated, just a window and a button in it, such as this XAML

<?xml version="1.0" encoding="utf-8"?>
<Window
    x:Class="App1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App1"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
        <Button x:Name="myButton" Click="myButton_Click">Click Me</Button>
    </StackPanel>
</Window>

What I’ve tried so far

I’ve created a fully working WinUI3 app in Visual Studio 2022 using the latest WindowsApps SDK. Then inside of the Winui3 projectApp1binx64Debugnet8.0-windows10.0.22621.0win-x64 folder I’ve tried loading all of the DLLs in there in PowerShell. Some 200 dlls loaded and a few failed to load.

In PowerShell now I have access to the type [Microsoft.UI.Xaml.Window] but when I try to create an instance of it

New-Object -TypeName Microsoft.UI.Xaml.Window
# Or
[Microsoft.UI.Xaml.Window]::new()

I get the following error

MethodInvocationException: Exception calling ".ctor" with "0" argument(s): "The type initializer for '_IWindowFactory' threw an exception."

It looks like there is a dependency missing for _IWindowFactory.

Other people have tried this too and had similar results. Another issue related to this problem asking for some guidance from Microsoft.

I don’t know how Visual Studio does this that makes it all so easy and automated, but I believe I need to do the same tasks manually in PowerShell.