VBA中使用计时器的两种方法

'================================
' VBA采用Application.OnTime实现计时器
'
' http://www.cnhup.com
'================================
Public RunWhen As Double
Public Const cRunIntervalSeconds =  ' two minutes
Public Const cRunWhat = "TheSub"  ' the name of the procedure to run
Sub StartTimer()
    RunWhen = Now + TimeSerial(,,cRunIntervalSeconds)
    Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, _
        Schedule:=True
End Sub
Sub TheSub()
    StartTimer  ' Reschedule the procedure
End Sub
Sub StopTimer()
    On Error Resume Next
    Application.OnTime EarliestTime:=RunWhen,Procedure:=cRunWhat, _
        Schedule:=False
End Sub

'================================
' VBA采用Windows API实现计时器
'
' http://www.cnhup.com
'================================
Public Declare Function SetTimer Lib "user32" ( _
    ByVal HWnd As Long, _
    ByVal nIDEvent As Long, _
    ByVal uElapse As Long, _
    ByVal lpTimerFunc As Long) As Long

Public Declare Function KillTimer Lib "user32" ( _
    ByVal HWnd As Long, _
    ByVal nIDEvent As Long) As Long

Public TimerID As Long
Public TimerSeconds As Single

Sub StartTimer()
    TimerSeconds =  ' how often to "pop" the timer.
    TimerID = SetTimer(&, &, TimerSeconds * &, AddressOf TimerProc)
End Sub

Sub EndTimer()
    On Error Resume Next
    KillTimer &, TimerID
End Sub

Sub TimerProc(ByVal HWnd As Long, ByVal uMsg As Long, _
        ByVal nIDEvent As Long, ByVal dwTimer As Long)

    ''''''
    ' This procedure is called by Windows. Put your
    ' code here.
    ''''''
End Sub