使用IF或Select Case在Excel UDF中获得更好的性能

2023年11月11日 237次阅读

我经常需要在Excel中搜索单元格中某些特殊文本的公式.我需要搜索的行数为100.000到500.000,在极少数情况下高达1.000.000.为了避免长公式,我编写了一个自己的UDF来搜索单元格中的多个文本字符串.新公式很难处理.我尽可能地优化了这个公式的运行时间. 500.000行需要11到12秒.

我用两种方式制作了这个公式：一个使用IF语句(SuchenSIF),另一个(SuchenSSELCASE)使用SELECT CASE语句.展位公式具有相同的速度.你能给我一些提示如何获得更好的表现吗？

该公式的语法是：
SuchenSIF(要搜索的单元格,要搜索的文本1,…要搜索的文本6)
SuchenSSELCASE(要搜索的单元格,要搜索的文本1,…要搜索的文本6)

Public Function SuchenSIF(Zelle As Range, such1 As String, Optional such2 As String, Optional such3 As String, Optional such4 As String, Optional such5 As String, Optional such6 As String) As Integer
Application.Volatile

' this code, based on IF-statements need 11-12 seconds for 500.000 rows
' Start of IF-Section
'
ZelleWert = Zelle.Value
SuchenS = InStr(1, ZelleWert, such1, vbTextCompare)
If SuchenS > 0 Then Exit Function
SuchenS = InStr(1, ZelleWert, such2, vbTextCompare)
If SuchenS <> vbFalse Then Exit Function
If Len(such3) > 0 Then
    SuchenS = InStr(1, ZelleWert, such3, vbTextCompare)
    If SuchenS > 0 Then Exit Function
    If Len(such4) > 0 Then
        SuchenS = InStr(1, ZelleWert, such4, vbTextCompare)
        If SuchenS > 0 Then Exit Function
        If Len(such5) > 0 Then
            SuchenS = InStr(1, ZelleWert, such5, vbTextCompare)
            If SuchenS > 0 Then Exit Function
            If Len(such6) > 0 Then
                SuchenS = InStr(1, ZelleWert, such6, vbTextCompare)
                If SuchenS > 0 Then Exit Function
            End If
        End If
    End If
End If
'
' End of IF-Section
If SuchenS = 0 Then SuchenS = False
End Function

Public Function SuchenSSELCASE(Zelle As Range, such1 As String, Optional such2 As String, Optional such3 As String, Optional such4 As String, Optional such5 As String, Optional such6 As String) As Integer
Application.Volatile
' this code, based on SELECT-CASE-statements need 11-12 seconds for 500.000 rows
' Start of SELECT-CASE -Section
'
ZelleWert = Zelle.Value
SuchenS = InStr(1, ZelleWert, such1, vbTextCompare) * Len(such1)
Select Case SuchenS
    Case 0
        SuchenS = InStr(1, ZelleWert, such2, vbTextCompare) * Len(such2)
        Select Case SuchenS
            Case 0
                SuchenS = InStr(1, ZelleWert, such3, vbTextCompare) * Len (such3)
                Select Case SuchenS
                    Case 0
                        SuchenS = InStr(1, ZelleWert, such4, vbTextCompare) * Len(such4)
                        Select Case SuchenS
                            Case 0
                                SuchenS = InStr(1, ZelleWert, such5, vbTextCompare) * Len(such5)
                                Select Case SuchenS
                                    Case 0
                                        SuchenS = InStr(1, ZelleWert, such6, vbTextCompare) * Len(such6)
                                        Select Case SuchenS
                                            Case 0
                                            Case Else
                                                SuchenS = SuchenS / Len(such6)
                                                Exit Function
                                        End Select
                                    Case Else
                                        SuchenS = SuchenS / Len(such5)
                                        Exit Function
                                End Select
                            Case Else
                                SuchenS = SuchenS / Len(such4)
                                Exit Function
                        End Select
                    Case Else
                        SuchenS = SuchenS / Len(such3)
                        Exit Function
                End Select
            Case Else
                SuchenS = SuchenS / Len(such2)
                Exit Function
        End Select
    Case Else
        SuchenS = SuchenS / Len(such1)
        Exit Function
End Select
'
' End of SELECT-CASE -Section
If SuchenS = 0 Then SuchenS = False
End Function

最佳答案 您可以通过在所有instr调用之前将单元格值转换为字符串一次来提高速度,而不是强制变量为每个调用进行字符串转换.

Dim ZelleWert as string
ZelleWert=Cstr(Zelle.Value2)

如果您有大量的UDF调用,则需要避免VBE Refresh错误：请参阅https://fastexcel.wordpress.com/2011/06/13/writing-efficient-vba-udfs-part-3-avoiding-the-vbe-refresh-bug/

如果您将UDF转换为处理单元格范围并返回结果数组,那么您可能会制作更快的UDF：请参阅
https://fastexcel.wordpress.com/2011/06/20/writing-efiicient-vba-udfs-part5-udf-array-formulas-go-faster/

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