The invocation of the constructor on type 'MahApps.Metro.Controls.MetroWindow' that matches the specified binding constraints threw an exception

[MERRiiii1]

Hey,

I am currently trying to understand how custom assemblies work with Powershell and WPF, but I'm really knew to all this and can't find any detailled tutorials on this, so I stumbled on this error and I need help to solve it...

I'm really new to custom assemblies so I don't really know how to use them with Powershell and Xaml. Here's what I did :

• Created new WPF project in VS and used Install-Package MahApps.Metro in PM Console
• Located the .dll files that were just downloaded, and copied it to a new directory named "Themes" in the WPF project subdirectory (tried multiple net versions)
• Created the .PS1 and modified the XAML according to the MahApps Quick Start guide (loading .dll assemblies in the script and changing the <Window ... </Window> tag to <mah:MetroWindow ... </mah:MetroWindow>.... and adding xmlns:mah="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"

The script

Add-Type -AssemblyName PresentationFramework
Add-Type -AssemblyName PresentationCore
Add-Type -AssemblyName WindowsBase
$AssemblyLocation = Join-Path -Path $PSScriptRoot -ChildPath .\Themes
foreach ($Assembly in (Dir $AssemblyLocation -Filter *.dll)) {
     [System.Reflection.Assembly]::LoadFrom($Assembly.fullName) | out-null
}
[System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") | Out-Null

$inputXML = Get-Content "$PSScriptRoot\MainWindow.xaml"
$inputXML = $inputXML -replace 'mc:Ignorable="d"', '' -replace "x:N", 'N' -replace '^<Win.*', '<Window'
[XML]$XAML = $inputXML


$reader = (New-Object System.Xml.XmlNodeReader $xaml)
try { $window = [Windows.Markup.XamlReader]::Load( $reader )
} catch { throw
}

$xaml.SelectNodes("//*[@Name]") | ForEach-Object {
    try { Set-Variable -Name "var_$($_.Name)" -Value $window.FindName($_.Name) -ErrorAction "Continue"
    } catch { throw
    }
}
$window.ShowDialog() | Out-Null

The XAML :

<mah:MetroWindow 
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:mah="http://metro.mahapps.com/winfx/xaml/controls"
        Title="MainWindow" Height="450" Width="800">

    <Grid>
    </Grid>

</mah:MetroWindow>

When launching the script I get this error :

Exception calling "Load" with "1" argument(s): "The invocation of the constructor on type 'MahApps.Metro.Controls.MetroWindow' that matches the specified binding constraints threw an exception.
+     $window = [Windows.Markup.XamlReader]::Load( $reader )
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : XamlParseException

I really don't know what to do now, I don't even know how to get details about this exception. Can someone help me ?

[MERRiiii1]

I've re-downloaded the .dll files and re-copied them, and now for some reasons, my Powershell sessions just die when I launch it ; no error, no popup, nothing. Didn't change the code, nothing explains the session being killed instantly

[timunie]

It's not really fair to open an issue for a question. Please close it and use Discussions for Q&As.

I can't answer here as I never used PS with MahApps, but maybe anyone else can if you attach a very minimal sample.