确定组合框的列表箱中一个特殊项是可见的
#include <GuiComboBox.au3>
_GUICtrlComboBox_SetTopIndex($hWnd, $iIndex)
| $hWnd | 控件的控件ID/句柄 | 
| $iIndex | 指定列表项从0开始的索引 | 
#include <GuiComboBox.au3>
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
$Debug_CB = False ;检查传递给 ComboBox/ComboBoxEx 函数的类名, 设置为True并输出到一个控件的句柄,用于检查它是否工作
_Main()
Func _Main()
    Local $hCombo
    ; 创建 GUI
    GUICreate("ComboBox Set Top Index", 400, 296)
    $hCombo = GUICtrlCreateCombo("", 2, 2, 396, 296, BitOR($CBS_SIMPLE, $CBS_DISABLENOSCROLL, $WS_VSCROLL))
    GUISetState()
    ; 添加文件
    _GUICtrlComboBox_BeginUpdate($hCombo)
    _GUICtrlComboBox_AddDir($hCombo, @WindowsDir & "\*.exe")
    _GUICtrlComboBox_EndUpdate($hCombo)
    ; Set Top Index
    _GUICtrlComboBox_SetTopIndex($hCombo, 10)
    ; Get Top Index
    MsgBox(4160, "信息", "Top Index:" & @TAB & _GUICtrlComboBox_GetTopIndex($hCombo))
    ; 循环直到用户退出
    Do
    Until GUIGetMsg() = $GUI_EVENT_CLOSE
    GUIDelete()
EndFunc   ;==>_Main