您如何测试VBA代码的运行时间? [英] How do you test running time of VBA code?

问题描述

VBA中是否有代码可以包装一个函数，让我知道运行时间，因此我可以比较函数的不同运行时间?

Is there code in VBA I can wrap a function with that will let me know the time it took to run, so that I can compare the different running times of functions?

推荐答案

除非您的函数很慢，否则您将需要一个非常高分辨率的计时器.我知道的最准确的是QueryPerformanceCounter.谷歌它的更多信息.尝试将以下内容推送到一个类中，称其为CTimer，然后可以在某个全局实例中创建一个实例，只需调用.StartCounter和.TimeElapsed

Unless your functions are very slow, you're going to need a very high-resolution timer. The most accurate one I know is QueryPerformanceCounter. Google it for more info. Try pushing the following into a class, call it CTimer say, then you can make an instance somewhere global and just call .StartCounter and .TimeElapsed

Option Explicit

Private Type LARGE_INTEGER
    lowpart As Long
    highpart As Long
End Type

Private Declare Function QueryPerformanceCounter Lib "kernel32" (lpPerformanceCount As LARGE_INTEGER) As Long
Private Declare Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency As LARGE_INTEGER) As Long

Private m_CounterStart As LARGE_INTEGER
Private m_CounterEnd As LARGE_INTEGER
Private m_crFrequency As Double

Private Const TWO_32 = 4294967296# ' = 256# * 256# * 256# * 256#

Private Function LI2Double(LI As LARGE_INTEGER) As Double
Dim Low As Double
    Low = LI.lowpart
    If Low < 0 Then
        Low = Low + TWO_32
    End If
    LI2Double = LI.highpart * TWO_32 + Low
End Function

Private Sub Class_Initialize()
Dim PerfFrequency As LARGE_INTEGER
    QueryPerformanceFrequency PerfFrequency
    m_crFrequency = LI2Double(PerfFrequency)
End Sub

Public Sub StartCounter()
    QueryPerformanceCounter m_CounterStart
End Sub

Property Get TimeElapsed() As Double
Dim crStart As Double
Dim crStop As Double
    QueryPerformanceCounter m_CounterEnd
    crStart = LI2Double(m_CounterStart)
    crStop = LI2Double(m_CounterEnd)
    TimeElapsed = 1000# * (crStop - crStart) / m_crFrequency
End Property

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