Dein System sollte so gehen:
[autoit]Case $nMsg = $Button1
$a = 0
While $a <=12
GUICtrlSetState(Eval("$TreeView1_" & $a), $GUI_CHECKED)
$a = $a + 1
WEnd
Ich würde es so machen:
[autoit]Dim $Tree[12]
$Tree[0] = GUICTRLCreateTreeView(...)
$Tree[1] = GUICTRLCreateTreeView(...)
;[usw.]
For $i = 0 to Ubound($Tree) -1
GUICtrlSetState($Tree[$i], $GUI_CHECKED)
Next
peethebee