Powershell WPF DataTemplate _click

$global:CurrentLocation = Get-Location

function SetMainWindow($Picture, $HeaderText, $Text)
{
    #region Controls
    $tMain = $WindowMain.FindName("tMain")
    $tHeader = $WindowMain.FindName("tHeader")
    $iMain = $WindowMain.FindName("iMain")
    $MainBorder = $WindowMain.FindName("MainBorder")
    #endregion

    $WindowMain.FindName("MainBackground").Background = "#FF076A80"

    $ScreenRes = [System.Windows.SystemParameters]::PrimaryScreenWidth
    if ($ScreenRes)
    {
        $WindowMain.Left = $Screenres - $WindowMain.Width
    }

}

$readerMain = (New-Object System.Xml.XmlNodeReader $xamlMain)
$WindowMain = [Windows.Markup.XamlReader]::Load($readerMain)

#region Controls
$btnTest = $WindowMain.FindName("btnTest")
$listBox = $WindowMain.FindName("listBox")
$label = $WindowMain.FindName("label")
#endregion

$WindowMain.FindName("btnTest").Add_click({
        $label.Content = "Normal button clicked"
    })

$WindowMain.FindName("btnRemoveOSCollEntry").Add_click({
        $label.Content = "DataTemplate button clicked"
    })

$DataSource = @()
$obj = New-Object PSCustomObject
$obj | Add-Member -MemberType 'NoteProperty' -Name Title -Value "Test title"
$DataSource += $obj
$listBox.ItemsSource = $DataSource

$WindowMain.ShowDialog() | Out-Null
Exit 0