Windows Software, bei Änderung einer Text-Datei auf einem Webserver eine Meldung

# url to load text content from 
$URL = "https://domain.tld/file.txt"  
# request interval
$INTERVAL_SECONDS = 60
# content to display
$DISPLAY_TEXT = "Inhalt der Datei hat sich geändert! Bitte mit OK bestätigen."    
# =============
Add-Type -A System.Windows.Forms
Add-Type -A System.Drawing
# webclient
$wc = New-Object System.Net.WebClient -P @{Encoding = [System.Text.Encoding]::UTF8}
# fullscreen form
$form = New-Object System.Windows.Forms.Form -Property @{
    Size = '200,200'    
    WindowState = 'Maximized'    
    TopMost = $true
    BackColor = [System.Drawing.Color]::Blue
    ControlBox = $false
    FormBorderStyle ='None'    
}
$txtInfo = New-Object System.Windows.Forms.Label -Property @{
    Dock = [System.Windows.Forms.DockStyle]::Fill
    TextAlign = 'MiddleCenter'    
    Font = New-Object System.Drawing.Font("Calibri",25,[System.Drawing.FontStyle]::Regular)    
    Text = $DISPLAY_TEXT
    ForeColor = [System.Drawing.Color]::White
    Size = '200,200'    
}
$btn = New-Object System.Windows.Forms.Button -Property @{
    Size = '150,50'    
    Location = '0,0'    
    Text = 'OK'    
    Font = New-Object System.Drawing.Font("Calibri",15,[System.Drawing.FontStyle]::Bold)    
    ForeColor = [System.Drawing.Color]::White
    BackColor = [System.Drawing.Color]::Green
}
$form.add_Load({
    $btn.Left = ([System.Windows.Forms.Screen]::PrimaryScreen.Bounds.Width / 2) - ($btn.Width/2)
    $btn.Top = [System.Windows.Forms.Screen]::PrimaryScreen.Bounds.Height - 200
})
$btn.add_Click({
    $form.Close()
})
$form.Controls.AddRange(@($btn,$txtInfo))

# get content from web scriptblock
$get_url_content = {
    try{
        return $wc.DownloadString($URL)
    }catch{
        write-host "Error loading file: $($_.Exception.Message)." -F Red  
        return $null
    }
}
# get initial content
$last = .$get_url_content

write-host "Waiting for changes ..." -F Green  
while($true){
    # get current value 
    $current = .$get_url_content
    # if value changed display fullscreen message
    if($current -ne $null -and $last -ne $current){
        [void]$form.ShowDialog()
        $last = $current
    }
    sleep -Seconds $INTERVAL_SECONDS
}