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 ExplicitType LARGE_INTEGER　　lowpart As Long　　highpart As LongEnd TypePublic Declare Function QueryPerformanceCounter Lib "kernel32" _　　　　(lpPerformanceCount As LARGE_INTEGER) As LongPublic Declare Function QueryPerformanceFrequency Lib "kernel32" _　　　　(lpFrequency As LARGE_INTEGER) As LongPublic 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 LongPublic Declare Function timeKillEvent Lib "winmm.dll" (ByVal uID As Long) As LongPublic Declare Function GetTickCount Lib "kernel32" () As LongPublic lMSFreq As LongPublic TimerCount As SinglePublic lmmCount As SinglePublic lTimeID As LongPublic actTime1 As LongPublic actTime2 As LongPublic iCountStart As SingleDim 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$(lmmCount, "00.00")　　lmmCount = lmmCount - 0.01　　If lmmCount = 0 Then　　　　iCountStart = 60　　　　lmmCount = 60　　　　TimerCount = 60　　　　EndCount　　End IfEnd SubSub EndCount()　　iCount = iCountStart　　iCountStart = 0　　timeKillEvent lTimeID　　actTime2 = GetTickCount - actTime1　　With Form1　　　　.Command1.Enabled = True　　　　.Command2.Enabled = False　　　　.Timer1.Enabled = False　　　　　　　　.Text1 = "计数器记时" + Format$((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 WithEnd Sub