#include <GUIScrollBars_Ex.au3>

$left = 5 ; The distance of the labels from the left edge of the window
$top = 10 ; First label's distance from the top edge of the window
$width = 100 ; Width of labels
$height = 25 ; Height of labels
$row_spacing = 30 ; Vertical distance between the labels

$GUI = GUICreate('Calculate exact scrollheight for dynamic labels after maximize window')

For $i = 1 To 50
	GUICtrlCreateLabel('Label ' & $i, $left, $top, $width, $height)
	GUICtrlSetBkColor(-1, 0xFFFFFF)
	$bot = $top + $height ; Bottom edge of the last label
	$top = $bot + $row_spacing ; Top of next label
Next

GUISetState()
$win = WinGetClientSize($GUI)
$norm = $win[1] ; Height of normal window

GUISetState(@SW_MAXIMIZE)
$win = WinGetClientSize($GUI)
$max = $win[1] ; Height of maximized window
$pegr = $max / $norm ; Percentage growth
$GUIScrollbarsHeight = ($bot * $pegr)

If $GUIScrollbarsHeight >= $max Then
	_GUIScrollbars_Generate($GUI, 0, $GUIScrollbarsHeight)			
EndIF

While 1
	$msg = GUIGetMsg()
	Switch $msg
		Case $GUI_EVENT_CLOSE
			Exit
	EndSwitch
Wend