Powershell WPF DataTemplate Button_click

[void][System.Reflection.Assembly]::LoadWithPartialName('presentationframework')
[void][System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
#Region Build the MAINWindow

[xml]$xamlMain = @"
<Window
        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:sys="clr-namespace:System;assembly=mscorlib"
        xmlns:local="clr-namespace:WW_Import"
        xmlns:Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero2"
    x:Name="Window" Title="MainWindow"  Height="350" Width="525">
    <Grid>
        <Button x:Name="btnTest" Content="Button" HorizontalAlignment="Left" Margin="202,223,0,0" VerticalAlignment="Top" Width="75"/>
        <ListBox x:Name="listBox" HorizontalAlignment="Left" Height="105" Margin="30,40,0,0" VerticalAlignment="Top" Width="429">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid Margin="0,2">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="190" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <Button  x:Name="btnRemoveOSCollEntry" Content="X"/>
                        <TextBlock Margin="10,0,0,0" Grid.Column="2" Text="{Binding Title}" />
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <Label x:Name="label" Content="Label" HorizontalAlignment="Left" Margin="147,164,0,0" VerticalAlignment="Top" Width="247"/>
    </Grid>
</Window>
"@
#endregion

$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