WPF Datagrid with powershell using class to implement INotifyPropertyChanged - still not working

datagrid-withclass.ps1

Using Namespace System.ComponentModel

Class ViewModel : INotifyPropertyChanged {
    Hidden [PropertyChangedEventHandler] $PropertyChanged
    [String]                             $ServerInstance
    [String]                             $targetAccount
    [Boolean]                            $isEverythingDone
    [String]                             $Status

    [Void] add_PropertyChanged([PropertyChangedEventHandler] $propertyChanged) {
        $this.PropertyChanged = [Delegate]::Combine($this.PropertyChanged, $propertyChanged)
    }

    [Void] remove_PropertyChanged([PropertyChangedEventHandler] $propertyChanged) {
        $this.PropertyChanged = [Delegate]::Remove($this.PropertyChanged, $propertyChanged)
    }

    Hidden [Void] NotifyPropertyChanged([String] $propertyName) {
        If ($this.PropertyChanged -cne $null) {
            $this.PropertyChanged.Invoke($this, (New-Object PropertyChangedEventArgs $propertyName))
        }
    }

}

[ViewModel] $viewModel = New-Object ViewModel -Property @{
    ServerInstance    = 'MyServer'
    targetAccount     = 'svcAccount'
    isEverythingDone  = $false
    Status            = ''
}

#-------------------------------------------------------------#
#----Initial Declarations-------------------------------------#
#-------------------------------------------------------------#

Add-Type -AssemblyName PresentationCore, PresentationFramework

$Xaml = @"
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" Width="800" Height="300" Name="khsdeflpnonyb">
  <Grid>
    <Grid.RowDefinitions>
      <RowDefinition Height="50"/>
      <RowDefinition Height="200"/>
    </Grid.RowDefinitions>
    <StackPanel Orientation="Horizontal">
      <Button Content="Update" HorizontalAlignment="Left" VerticalAlignment="Top" Width="100" Margin="6" Grid.Row="0" Grid.Column="0" Name="updateButton"/>
      <Button Content="Update Async" HorizontalAlignment="Left" VerticalAlignment="Top" Width="100" Margin="6" Grid.Row="0" Grid.Column="0" Name="updateButtonASync"/>
      <Button Content="Refresh" HorizontalAlignment="Left" VerticalAlignment="Top" Width="100" Margin="6" Grid.Row="0" Grid.Column="0" Name="refreshButton"/>
    </StackPanel>
    <DataGrid Grid.Row="1" Name="observableDataGrid" IsReadOnly="True" Margin="6" ItemsSource="{Binding serverList}" SelectedItem="{Binding selectedServer}">
    </DataGrid>
  </Grid>
</Window>

"@

#-------------------------------------------------------------#
#----Control Event Handlers-----------------------------------#
#-------------------------------------------------------------#


#Write your code here
function UpdateButton
{
    $State.selectedServer.Status = (Get-Random | Out-String)
    #$observableDataGrid.Items.Refresh()
}

function UpdateButtonAsync
{
    Async {
    $State.selectedServer.Status = (Get-Random | Out-String)
    }
}

function Refresh
{
    $observableDataGrid.Items.Refresh()
}

function OnLoad
{
    $results = New-Object 'System.Collections.ObjectModel.ObservableCollection[ViewModel]'
    
    $results.Add($viewModel)
    
    $observableDataGrid.itemsSource = $results  

}
#endregion

#-------------------------------------------------------------#
#----Script Execution-----------------------------------------#
#-------------------------------------------------------------#

$Window = [Windows.Markup.XamlReader]::Parse($Xaml)

[xml]$xml = $Xaml

$xml.SelectNodes("//*[@Name]") | ForEach-Object { Set-Variable -Name $_.Name -Value $Window.FindName($_.Name) }


$khsdeflpnonyb.Add_Loaded({OnLoad $this $_})
$updateButton.Add_Click({UpdateButton $this $_})
$updateButtonASync.Add_Click({UpdateButtonASync $this $_})
$refreshButton.Add_Click({Refresh $this $_})

$State = [PSCustomObject]@{}


Function Set-Binding {
    Param($Target,$Property,$Index,$Name)
 
    $Binding = New-Object System.Windows.Data.Binding
    $Binding.Path = "["+$Index+"]"
    $Binding.Mode = [System.Windows.Data.BindingMode]::TwoWay
    


    [void]$Target.SetBinding($Property,$Binding)
}

function FillDataContext($props){

    For ($i=0; $i -lt $props.Length; $i++) {
   
   $prop = $props[$i]
   $DataContext.Add($DataObject."$prop")
   
    $getter = [scriptblock]::Create("return `$DataContext['$i']")
    $setter = [scriptblock]::Create("param(`$val) return `$DataContext['$i']=`$val")
    $State | Add-Member -Name $prop -MemberType ScriptProperty -Value  $getter -SecondValue $setter
               
       }
   }



$DataObject =  ConvertFrom-Json @"

{
    "serverList" : [{
        "ServerInstance" : "",
        "targetAccount" : "",
        "isEverythingDone" : "",
        "Status": ""
    }],
    "selectedServer":""
}

"@

$DataContext = New-Object System.Collections.ObjectModel.ObservableCollection[Object]
FillDataContext @("serverList","selectedServer") 

$Window.DataContext = $DataContext
Set-Binding -Target $observableDataGrid -Property $([System.Windows.Controls.DataGrid]::ItemsSourceProperty) -Index 0 -Name "serverList"
Set-Binding -Target $observableDataGrid -Property $([System.Windows.Controls.DataGrid]::SelectedItemProperty) -Index 1 -Name "selectedServer"




$Global:SyncHash = [HashTable]::Synchronized(@{})
$Jobs = [System.Collections.ArrayList]::Synchronized([System.Collections.ArrayList]::new())
$initialSessionState = [initialsessionstate]::CreateDefault()

Function Start-RunspaceTask
{
    [CmdletBinding()]
    Param([Parameter(Mandatory=$True,Position=0)][ScriptBlock]$ScriptBlock,
          [Parameter(Mandatory=$True,Position=1)][PSObject[]]$ProxyVars)
            
    $Runspace = [RunspaceFactory]::CreateRunspace($InitialSessionState)
    $Runspace.ApartmentState = 'STA'
    $Runspace.ThreadOptions  = 'ReuseThread'
    $Runspace.Open()
    ForEach($Var in $ProxyVars){$Runspace.SessionStateProxy.SetVariable($Var.Name, $Var.Variable)}
    $Thread = [PowerShell]::Create('NewRunspace')
    $Thread.AddScript($ScriptBlock) | Out-Null
    $Thread.Runspace = $Runspace
    [Void]$Jobs.Add([PSObject]@{ PowerShell = $Thread ; Runspace = $Thread.BeginInvoke() })
}

$JobCleanupScript = {
    Do
    {    
        ForEach($Job in $Jobs)
        {            
            If($Job.Runspace.IsCompleted)
            {
                [Void]$Job.Powershell.EndInvoke($Job.Runspace)
                $Job.PowerShell.Runspace.Close()
                $Job.PowerShell.Runspace.Dispose()
                $Runspace.Powershell.Dispose()
                
                $Jobs.Remove($Runspace)
            }
        }

        Start-Sleep -Seconds 1
    }
    While ($SyncHash.CleanupJobs)
}

Get-ChildItem Function: | Where-Object {$_.name -notlike "*:*"} |  select name -ExpandProperty name |
ForEach-Object {       
    $Definition = Get-Content "function:$_" -ErrorAction Stop
    $SessionStateFunction = New-Object System.Management.Automation.Runspaces.SessionStateFunctionEntry -ArgumentList "$_", $Definition
    $InitialSessionState.Commands.Add($SessionStateFunction)
}


$Window.Add_Closed({
    Write-Verbose 'Halt runspace cleanup job processing'
    $SyncHash.CleanupJobs = $False
})

$SyncHash.CleanupJobs = $True
function Async($scriptBlock){ Start-RunspaceTask $scriptBlock @([PSObject]@{ Name='DataContext' ; Variable=$DataContext},[PSObject]@{Name="State"; Variable=$State})}

Start-RunspaceTask $JobCleanupScript @([PSObject]@{ Name='Jobs' ; Variable=$Jobs })



$Window.ShowDialog()

$Class = @'
using System.ComponentModel;

public class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private string _ServerInstance;
    public string ServerInstance
    {
        get { return _ServerInstance; }
        set
        {
            _ServerInstance = value;

            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("ServerInstance"));
        }
    }

    private string _targetAccount;
    public string targetAccount
    {
        get { return _targetAccount; }
        set
        {
            _targetAccount = value;

            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("targetAccount"));
        }
    }

    private bool _isEverythingDone;
    public bool isEverythingDone
    {
        get { return _isEverythingDone; }
        set
        {
            _isEverythingDone = value;

            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("isEverythingDone"));
        }
    }

    private string _Status;
    public string Status
    {
        get { return _Status; }
        set
        {
            _Status = value;

            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("Status"));
        }
    }
}
'@

Add-Type -TypeDefinition $Class -Language 'CSharp'
[ViewModel]::New()

Try importing the class this way.