VB.NET如何实现精确延时 1ms

[spark_li]

System.Threading.Thread.Sleep(1) 误差挺大的，
不知道有什么好的解决办法，谢谢

[Tiger_Zhao]

Windows任务调度的时间片是几十毫秒级的，误差大是很正常的。
多任务系统下是做不到精确延时的。

[郗晓勇]

http://goobbe.com/questions/3890239/how-do-i-get-my-c-sharp-program-to-sleep-for-50-msec

[鏡椛氹鈅]

引用 楼主 spark_li 的回复:

System.Threading.Thread.Sleep(1) 误差挺大的， 不知道有什么好的解决办法，谢谢

http://bbs.csdn.net/topics/390977274

[finalfly]

最好把整个环境说明白

[本拉灯]

这基本没招，除非你能像控制寄存器那样。用位值操作。

[dunewer]

可以精确到us。 Dim sw As New Stopwatch sw.Start() Dim LngA As Long = sw.ElapsedTicks Do If sw.ElapsedMilliseconds - LngA >= 12222 Then LngA = sw.ElapsedTicks End If Loop sw.Stop()

[Tiger_Zhao]

#6: 没用的，任务调度把你的进程挂起，能算到纳秒都没用。
精确计时要在单片机上实现，程序定时读取外设上缓存的数据。

[以专业开发人员为伍]

Sleep并不是用来定时的，它经过了复杂的操作系统任务调度机制，你怎么会想到用这么复杂的Sleep来计时？真不知道是从哪个奇怪的地方听说来的。 要定时，最起码地，是应该使用 System.Threading.Timer 对象（类）来定时。

[以专业开发人员为伍]

嗯，又看了一下你的问题。 基本上在桌面版的windows中，不可能有比操作系统调度线程上下文切换更“精确”的调度方法。如果你只是要1ms的延时，还要精确，那么你只能做底层 ring-0 层的开发去完成，不能做应用程序。

[ma0808sun]

Option Strict Off Option Explicit On Imports Microsoft.VisualBasic.Compatibility Public Class ClsWaitableTimer Private Structure FILETIME Dim dwLowDateTime As Integer Dim dwHighDateTime As Integer End Structure Private Const WAIT_ABANDONED As Integer = &H80 Private Const WAIT_ABANDONED_0 As Integer = &H80 Private Const WAIT_FAILED As Integer = -1 Private Const WAIT_IO_COMPLETION As Integer = &HC0 Private Const WAIT_OBJECT_0 As Integer = 0 Private Const WAIT_OBJECT_1 As Integer = 1 Private Const WAIT_TIMEOUT As Integer = &H102 Private Const INFINITE As Short = &HFFFFS Private Const ERROR_ALREADY_EXISTS As Short = 183 Private Const QS_HOTKEY As Integer = &H80S Private Const QS_KEY As Integer = &H1S Private Const QS_MOUSEBUTTON As Integer = &H4S Private Const QS_MOUSEMOVE As Integer = &H2S Private Const QS_PAINT As Integer = &H20S Private Const QS_POSTMESSAGE As Integer = &H8S Private Const QS_SENDMESSAGE As Integer = &H40S Private Const QS_TIMER As Integer = &H10S Private Const QS_MOUSE As Integer = (QS_MOUSEMOVE Or QS_MOUSEBUTTON) Private Const QS_INPUT As Integer = (QS_MOUSE Or QS_KEY) Private Const QS_ALLEVENTS As Integer = (QS_INPUT Or QS_POSTMESSAGE Or QS_TIMER Or QS_PAINT Or QS_HOTKEY) Private Const QS_ALLINPUT As Integer = (QS_SENDMESSAGE Or QS_PAINT Or QS_TIMER Or QS_POSTMESSAGE Or QS_MOUSEBUTTON Or QS_MOUSEMOVE Or QS_HOTKEY Or QS_KEY) Private Const UNITS As Double = 4294967296.0# Private Const MAX_LONG As Double = -2147483648.0# Private Declare Function CreateWaitableTimer Lib "kernel32" Alias "CreateWaitableTimerA" (ByVal lpSemaphoreAttributes As Integer, ByVal bManualReset As Integer, ByVal lpName As String) As Integer Private Declare Function OpenWaitableTimer Lib "kernel32" Alias "OpenWaitableTimerA" (ByVal dwDesiredAccess As Integer, ByVal bInheritHandle As Integer, ByVal lpName As String) As Integer 'UPGRADE_WARNING: 结构 FILETIME 可能要求封送处理属性作为此声明语句中的参数传递。 单击以获得更多信息:“ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="vbup1050"” Private Declare Function SetWaitableTimer Lib "kernel32" (ByVal hTimer As Integer, ByRef lpDueTime As FILETIME, ByVal lPeriod As Integer, ByVal pfnCompletionRoutine As Integer, ByVal lpArgToCompletionRoutine As Integer, ByVal fResume As Integer) As Integer Private Declare Function CancelWaitableTimer Lib "kernel32" (ByVal hTimer As Integer) As Object Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Integer) As Integer Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Integer, ByVal dwMilliseconds As Integer) As Integer Private Declare Function MsgWaitForMultipleObjects Lib "user32" (ByVal nCount As Integer, ByRef pHandles As Integer, ByVal fWaitAll As Integer, ByVal dwMilliseconds As Integer, ByVal dwWakeMask As Integer) As Integer Private mlTimer As Integer Public GWNO As String Public aaa As String 'UPGRADE_NOTE: Class_Terminate 已升级到 Class_Terminate_Renamed。 单击以获得更多信息:“ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="vbup1061"” Private Sub Class_Terminate_Renamed() On Error Resume Next If mlTimer <> 0 Then CloseHandle(mlTimer) End Sub Protected Overrides Sub Finalize() Class_Terminate_Renamed() MyBase.Finalize() End Sub Public Sub Wait(ByRef MilliSeconds As Integer) On Error GoTo ErrHandler Dim ft As FILETIME Dim lBusy As Integer Dim lRet As Integer Dim dblDelay As Double Dim dblDelayLow As Double aaa = Trim(GWNO) & "Timer" & VB6.Format(Now, "NNSS") 'mlTimer = CreateWaitableTimer(0, True, VB6.GetEXEName() & "Timer" & VB6.Format(Now, "NNSS")) mlTimer = CreateWaitableTimer(0, True, Trim(GWNO) & "Timer" & VB6.Format(Now, "NNSS")) If Err.LastDllError <> ERROR_ALREADY_EXISTS Then ft.dwLowDateTime = -1 ft.dwHighDateTime = -1 lRet = SetWaitableTimer(mlTimer, ft, 0, 0, 0, 0) End If ' Convert the Units to nanoseconds. dblDelay = CDbl(MilliSeconds) * 10000.0# ' 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 = -CInt(dblDelay / UNITS) - 1 dblDelayLow = -UNITS * (dblDelay / UNITS - Fix(CShort(CStr(dblDelay / UNITS)))) If dblDelayLow < MAX_LONG Then dblDelayLow = UNITS + dblDelayLow ft.dwLowDateTime = CInt(dblDelayLow) lRet = SetWaitableTimer(mlTimer, 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, mlTimer, False, INFINITE, QS_ALLINPUT) System.Windows.Forms.Application.DoEvents() Loop Until lBusy = WAIT_OBJECT_0 ' Close the handles when you are done with them. CloseHandle(mlTimer) mlTimer = 0 Exit Sub ErrHandler: Err.Raise(Err.Number, Err.Source, "[clsWaitableTimer.Wait]" & Err.Description) End Sub End Class

[ma0808sun]

上面那段代码 可以的 我一直是用那种做延时处理