Private Const WM_SYSCOMMAND = &H112&
Private Const SC_MONITORPOWER = &H170&
Private Declare Function SendMessage Lib "user32" Alias "SendMessagea" (ByVal hWnd As Long, ByVal wmsg As Long, ByVal param As Long, ByVal lparam As Long) As Long

OpenDisplay = IIf(SendMessage(Me.hWnd, WM_SYSCOMMAND, SC_MONITORPOWER, -1&) = 0, True, False)
CloseDisplay = IIf(SendMessage(Me.hWnd, WM_SYSCOMMAND, SC_MONITORPOWER, 1&) = 0, True, False)

希望各位能逐句的解释一下，还有能不能告诉我这几句话的作用。

[ 本帖最后由 小J 于 2009-10-12 17:13 编辑 ]

Const WM_SYSCOMMAND = &H112&  定义常量WM_SYSCOMMAND
Const SC_MONITORPOWER = &H170& 定义常量SC_MONITORPOWER

调用API函数SendMessage()关闭显示器，lparam=-1打开,lparam=1休眠 lparam=2关闭