vb实现高精度计时

'在Project中加入一个Module，然后在其中加入以下代码：
Option Explicit
Type LARGE_INTEGER
　　lowpart As Long
　　highpart As Long
End Type
Public Declare Function QueryPerformanceCounter Lib "kernel32" _
　　　　(lpPerformanceCount As LARGE_INTEGER) As Long
Public Declare Function QueryPerformanceFrequency Lib "kernel32" _
　　　　(lpFrequency As LARGE_INTEGER) As Long
Public Declare Function timeSetEvent Lib "winmm.dll" (ByVal uDelay As Long, ByVal _
　　　　uResolution As Long, ByVal lpFunction As Long, ByVal dwUser As Long, _
　　　　ByVal uFlags As Long) As Long
Public Declare Function timeKillEvent Lib "winmm.dll" (ByVal uID As Long) As Long
Public Declare Function GetTickCount Lib "kernel32" () As Long
Public lMSFreq As Long
Public TimerCount As Single
Public lmmCount As Single
Public lTimeID As Long
Public actTime1 As Long
Public actTime2 As Long
Public iCountStart As Single
Dim iCount As Single
'注释: timeSetEvent的回调函数
Sub TimeProc(ByVal uID As Long, ByVal uMsg As Long, ByVal dwUser As Long, _
　　ByVal dw1 As Long, ByVal dw2 As Long)
　　
　　Form1.Text2.Text = Format$(lmmCount, "00.00")
　　lmmCount = lmmCount - 0.01
　　If lmmCount <= 0 Then
　　　　iCountStart = 60
　　　　lmmCount = 60
　　　　TimerCount = 60
　　　　EndCount
　　End If
End Sub
Sub EndCount()
　　iCount = iCountStart
　　iCountStart = 0
　　timeKillEvent lTimeID
　　actTime2 = GetTickCount - actTime1
　　With Form1
　　　　.Command1.Enabled = True
　　　　.Command2.Enabled = False
　　　　.Timer1.Enabled = False
　　　　
　　　　.Text1 = "计数器记时" + Format$((60 - iCount), "00.00") + "　" _
　　　　　　　　+ "实际经过时间" + Format$((actTime2 / 1000), "00.00")
　　　　.Text2 = "计数器记时" + Format$((60 - lmmCount), "00.00") + "　" _
　　　　　　　　+ "实际经过时间" + Format$((actTime2 / 1000), "00.00")
　　　　.Text3 = "计数器记时" + Format$((60 - TimerCount), "00.00") + "　" _
　　　　　　　　+ "实际经过时间" + Format$((actTime2 / 1000), "00.00")
　　End With
End Sub