3种延时方法，那种好一些？请大家研究一下。（附代码）

irians 2001-12-03 11:43:52

第一种方法：
'在一个窗体中
'一个按纽 command1
'////////////////
Dim delay As Integer

Private Sub Command1_Click()
Timer1.Enabled = True
wait (5)
MsgBox "over"
Timer1.Enabled = False
End Sub

Private Sub Timer1_Timer()
delay = delay + 1
End Sub
Private Function wait(ByVal aaa As Integer)
Do While delay < aaa
DoEvents
Loop
delay = 0
End Function

第二种方法
'在一个窗体中
'两个按纽 command1，command2
'////////////////

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Declare Function SleepEx Lib "kernel32" (ByVal dwMilliseconds As Long, ByVal bAlertable As Long) As Long

'用: Sleep 2000
'或：Sleep 2000,false(不能被唤醒)
' Sleep 2000,True(可被唤醒)

Private Sub Command1_Click()
Sleep 5000
MsgBox "over"
End Sub

Private Sub Command2_Click()
SleepEx 5000, True
MsgBox "over"
End Sub

第三种方法：

'在一个窗体中
'一个按纽 command1
'////////////////
Option Explicit

Private Sub Command1_Click()
Wait (5)
MsgBox "over"
End Sub

'在一个标准模块中
'************************************************************************************
'定时控制
'************************************************************************************
Private Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type

Private Const WAIT_ABANDONED& = &H80&
Private Const WAIT_ABANDONED_0& = &H80&
Private Const WAIT_FAILED& = -1&
Private Const WAIT_IO_COMPLETION& = &HC0&
Private Const WAIT_OBJECT_0& = 0
Private Const WAIT_OBJECT_1& = 1
Private Const WAIT_TIMEOUT& = &H102&

Private Const INFINITE = &HFFFF
Private Const ERROR_ALREADY_EXISTS = 183&

Private Const QS_HOTKEY& = &H80
Private Const QS_KEY& = &H1
Private Const QS_MOUSEBUTTON& = &H4
Private Const QS_MOUSEMOVE& = &H2
Private Const QS_PAINT& = &H20
Private Const QS_POSTMESSAGE& = &H8
Private Const QS_SENDMESSAGE& = &H40
Private Const QS_TIMER& = &H10
Private Const QS_MOUSE& = (QS_MOUSEMOVE _
Or QS_MOUSEBUTTON)
Private Const QS_INPUT& = (QS_MOUSE _
Or QS_KEY)
Private Const QS_ALLEVENTS& = (QS_INPUT _
Or QS_POSTMESSAGE _
Or QS_TIMER _
Or QS_PAINT _
Or QS_HOTKEY)
Private Const QS_ALLINPUT& = (QS_SENDMESSAGE _
Or QS_PAINT _
Or QS_TIMER _
Or QS_POSTMESSAGE _
Or QS_MOUSEBUTTON _
Or QS_MOUSEMOVE _
Or QS_HOTKEY _
Or QS_KEY)

Private Declare Function CreateWaitableTimer Lib "kernel32" _
Alias "CreateWaitableTimerA" ( _
ByVal lpSemaphoreAttributes As Long, _
ByVal bManualReset As Long, _
ByVal lpName As String) As Long

Private Declare Function OpenWaitableTimer Lib "kernel32" _
Alias "OpenWaitableTimerA" ( _
ByVal dwDesiredAccess As Long, _
ByVal bInheritHandle As Long, _
ByVal lpName As String) As Long

Private Declare Function SetWaitableTimer Lib "kernel32" ( _
ByVal hTimer As Long, _
lpDueTime As FILETIME, _
ByVal lPeriod As Long, _
ByVal pfnCompletionRoutine As Long, _
ByVal lpArgToCompletionRoutine As Long, _
ByVal fResume As Long) As Long

Public Declare Function CancelWaitableTimer Lib "kernel32" ( _
ByVal hTimer As Long)

Public Declare Function CloseHandle Lib "kernel32" ( _
ByVal hObject As Long) As Long

Private Declare Function WaitForSingleObject Lib "kernel32" ( _
ByVal hHandle As Long, _
ByVal dwMilliseconds As Long) As Long

Private Declare Function MsgWaitForMultipleObjects Lib "user32" ( _
ByVal nCount As Long, _
pHandles As Long, _
ByVal fWaitAll As Long, _
ByVal dwMilliseconds As Long, _
ByVal dwWakeMask As Long) As Long

Private Declare Function GetLastError Lib "kernel32" () As Long

'************************************************************************************

Public hTimer As Long '定时器句柄

Public Sub Wait(lNumberOfSeconds As Long)
Dim ft As FILETIME
Dim lBusy As Long
Dim lRet As Long
Dim dblDelay As Double
Dim dblDelayLow As Double
Dim dblUnits As Double

Dim ErrCode As Long

On Error GoTo HELL

hTimer = CreateWaitableTimer(0, True, App.EXEName & "Timer")

If Err.LastDllError = ERROR_ALREADY_EXISTS Then

ErrCode = GetLastError()
If ErrCode <> 0 Then
'WriteErrLog Nothing, "Modinitial.Wait", 418, "Sysrem Error, Code: " & ErrCode
Err.Clear
End If
' If the timer already exists, it does not hurt to open it
' as long as the person who is trying to open it has the
' proper access rights.
Else
ft.dwLowDateTime = -1
ft.dwHighDateTime = -1
lRet = SetWaitableTimer(hTimer, ft, 0, 0, 0, 0)
End If

' Convert the Units to nanoseconds.
dblUnits = CDbl(&H10000) * CDbl(&H10000)
dblDelay = CDbl(lNumberOfSeconds) * 1000 * 10000

' By setting the high/low time to a negative number, it tells
' the Wait (in SetWaitableTimer) to use an offset time as
' opposed to a hardcoded time. If it were positive, it would
' try to convert the value to GMT.
ft.dwHighDateTime = -CLng(dblDelay / dblUnits) - 1
dblDelayLow = -dblUnits * (dblDelay / dblUnits - _
Fix(dblDelay / dblUnits))

If dblDelayLow < CDbl(&H80000000) Then
' &H80000000 is MAX_LONG, so you are just making sure
' that you don't overflow when you try to stick it into
' the FILETIME structure.
dblDelayLow = dblUnits + dblDelayLow
End If

ft.dwLowDateTime = CLng(dblDelayLow)
lRet = SetWaitableTimer(hTimer, ft, 0, 0, 0, False)

Do
' QS_ALLINPUT means that MsgWaitForMultipleObjects will
' return every time the thread in which it is running gets
' a message. If you wanted to handle messages in here you could,
' but by calling Doevents you are letting DefWindowProc
' do its normal windows message handling---Like DDE, etc.
lBusy = MsgWaitForMultipleObjects(1, hTimer, False, _
INFINITE, QS_ALLINPUT&)
DoEvents
Loop Until lBusy = WAIT_OBJECT_0

' Close the handles when you are done with them.
CloseHandle hTimer

Exit Sub

HELL:

ErrCode = GetLastError()
'WriteErrLog Nothing, "Modinitial.Wait", 476, "Sysrem Error, Code: " & ErrCode
Err.Clear
Resume Next

End Sub

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