如何利用API函数使Windows开始屏幕保护？

*API函数声明Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long Const WM_SYSCOMMAND = &H112& Const SC_SCREENSAVE = &HF140&注释：调用Dim result As Long result = SendMessage(Form1.hWnd, WM_SYSCOMMAND, SC_SCREENSAVE, 0&)