Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing

$global:bt_width = 150
$global:bt_hight = 23
$global:row_distance = 15

$global:bt_StartPosX = 35
$global:bt_StartPosY = -20
$global:bt_HightDiff = 25

$global:NrRows = 3
$global:arrCurPosX = New-Object 'Int16[]' $NrRows
$global:arrCurPosY = New-Object 'Int16[]' $NrRows
$i=0
while ($i -lt $NrRows){
    $arrCurPosX[$i] = $bt_StartPosX + $i*($bt_width+$row_distance)
    $arrCurPosY[$i] = $bt_StartPosY
    $i++
}

$global:form = New-Object System.Windows.Forms.Form

$global:ButtonScriptblock = {
    $txt = "Hi! I am the general scriptblock!"
    Write-Host $txt
    Show-Messagebox $txt
}

$global:ButtonResettedScriptblock = {
    $txt = "Hi! I am the resetted scriptblock!"
    Write-Host $txt
    Show-Messagebox $txt
}

function AddButton([String] $ButtonName, [int] $MyRow) {
    $MyRow = $MyRow - 1 
    $NewButton = New-Object System.Windows.Forms.Button
    $arrCurPosY[$MyRow] += $bt_HightDiff
    $NewButton.Location = New-Object System.Drawing.Size($arrCurPosX[$MyRow], $arrCurPosY[$MyRow])
    $NewButton.Size = New-Object System.Drawing.Size($bt_width, $bt_hight)
    $NewButton.Text = $ButtonName
    $NewButton.Add_Click($ButtonScriptblock)
    $Form.Controls.Add($NewButton)
    $NewButton = $null
    $global:ButtonScriptblock = $ButtonResettedScriptblock
}

function AddHeader([String] $HeaderTXT, [int] $MyRow) {
    $MyRow = $MyRow - 1 
    $NewText = New-Object System.Windows.Forms.Label
    $arrCurPosY[$MyRow] += 2 * $bt_HightDiff
    $NewText.Location = New-Object System.Drawing.Size($arrCurPosX[$MyRow], $arrCurPosY[$MyRow])
    $NewText.Size = New-Object System.Drawing.Size($bt_width, $bt_hight)
    $NewText.BackColor = 'white'
    $NewText.Text = $HeaderTXT
    $NewText.TextAlign ="MiddleCenter"
    $NewFontSize =     $NewText.Font.Size 
    $FontName = $NewText.Font.Name
    $FontStyle = "style=bold"
    $NewText.Font = "$FontName, $NewFontSize, $FontStyle"
    $Form.Controls.Add($NewText)
    $NewText = $null
}

function Show-MessageBox {
    # https://stackoverflow.com/questions/58718191/is-there-a-way-to-display-a-pop-up-message-box-in-powershell-that-is-compatible
    [CmdletBinding(PositionalBinding=$false)]
    param(
      [Parameter(Mandatory, Position=0)]
      [string] $Message,
      [Parameter(Position=1)]
      [string] $Title,
      [Parameter(Position=2)]
      [ValidateSet('OK', 'OKCancel', 'AbortRetryIgnore', 'YesNoCancel', 'YesNo', 'RetryCancel')]
      [string] $Buttons = 'OK',
      [ValidateSet('Information', 'Warning', 'Stop')]
      [string] $Icon = 'Information',
      [ValidateSet(0, 1, 2)]
      [int] $DefaultButtonIndex
    )
  
    # So that the $IsLinux and $IsMacOS PS Core-only
    # variables can safely be accessed in WinPS.
    Set-StrictMode -Off
  
    $buttonMap = @{ 
      'OK'               = @{ buttonList = 'OK'; defaultButtonIndex = 0 }
      'OKCancel'         = @{ buttonList = 'OK', 'Cancel'; defaultButtonIndex = 0; cancelButtonIndex = 1 }
      'AbortRetryIgnore' = @{ buttonList = 'Abort', 'Retry', 'Ignore'; defaultButtonIndex = 2; ; cancelButtonIndex = 0 }; 
      'YesNoCancel'      = @{ buttonList = 'Yes', 'No', 'Cancel'; defaultButtonIndex = 2; cancelButtonIndex = 2 };
      'YesNo'            = @{ buttonList = 'Yes', 'No'; defaultButtonIndex = 0; cancelButtonIndex = 1 }
      'RetryCancel'      = @{ buttonList = 'Retry', 'Cancel'; defaultButtonIndex = 0; cancelButtonIndex = 1 }
    }
  
    $numButtons = $buttonMap[$Buttons].buttonList.Count
    $defaultIndex = [math]::Min($numButtons - 1, ($buttonMap[$Buttons].defaultButtonIndex, $DefaultButtonIndex)[$PSBoundParameters.ContainsKey('DefaultButtonIndex')])
    $cancelIndex = $buttonMap[$Buttons].cancelButtonIndex
  
    if ($IsLinux) { 
      Throw "Not supported on Linux." 
    }
    elseif ($IsMacOS) {
  
      $iconClause = if ($Icon -ne 'Information') { 'as ' + $Icon -replace 'Stop', 'critical' }
      $buttonClause = "buttons { $($buttonMap[$Buttons].buttonList -replace '^', '"' -replace '$', '"' -join ',') }"
  
      $defaultButtonClause = 'default button ' + (1 + $defaultIndex)
      if ($null -ne $cancelIndex -and $cancelIndex -ne $defaultIndex) {
        $cancelButtonClause = 'cancel button ' + (1 + $cancelIndex)
      }
  
      $appleScript = "display alert `"$Title`" message `"$Message`" $iconClause $buttonClause $defaultButtonClause $cancelButtonClause"            #"
  
      Write-Verbose "AppleScript command: $appleScript"
  
      # Show the dialog.
      # Note that if a cancel button is assigned, pressing Esc results in an
      # error message indicating that the user canceled.
      $result = $appleScript | osascript 2>$null
  
      # Output the name of the button chosen (string):
      # The name of the cancel button, if the dialog was canceled with ESC, or the
      # name of the clicked button, which is reported as "button:<name>"
      if (-not $result) { $buttonMap[$Buttons].buttonList[$buttonMap[$Buttons].cancelButtonIndex] } else { $result -replace '.+:' }
    }
    else { # Windows
      Add-Type -Assembly System.Windows.Forms        
      # Show the dialog.
      # Output the chosen button as a stringified [System.Windows.Forms.DialogResult] enum value,
      # for consistency with the macOS behavior.
      [System.Windows.Forms.MessageBox]::Show($Message, $Title, $Buttons, $Icon, $defaultIndex * 256).ToString()
    }
}

$Click_Button1 = {
    $txt = "Hi! I am in scriptblock 1!"
    Write-Host $txt
    Show-Messagebox $txt
}

$Click_Button2 = {
    $txt = "Hi! I am in scriptblock 2!"
    Write-Host $txt
    Show-Messagebox $txt
}

$Click_Button3 = {
    $txt = "Hi! I am in scriptblock 3!"
    Write-Host $txt
    Show-Messagebox $txt
}

AddHeader "Spalte 1" 1
AddHeader "Spalte 2" 2

$ButtonScriptblock = $Click_Button1
AddButton "Button11" 1

$ButtonScriptblock = $Click_Button2
AddButton "Button12" 1

$ButtonScriptblock = $Click_Button3
AddButton "Button21" 2
AddButton "Button22" 2

$i=0
$maxPosX =0
$maxPosY =0

while ($i -lt $NrRows){
    if ($maxPosX -lt $arrCurPosX[$i]) {$maxPosX=$arrCurPosX[$i]}
    if ($maxPosY -lt $arrCurPosY[$i]) {$maxPosY=$arrCurPosY[$i]}
    $i++
}

$form.Width =$maxPosX + $bt_StartPosX
$form.Height =$maxPosY + 4 * $bt_hight

$form.text = "***Auer Signal Admin Menu ***"
$form.StartPosition = "CenterScreen" #Wird auf dem Hauptbildschirm zentriert angezeigt

$form.showdialog()