Question

我需要有关如何让代码执行得更快的帮助。我的数据量非常大，而我的“Dim WB1 As Workbook Dim ws1 As Worksheet Dim last As Long Dim i As Integer Dim x As String, y As String Set WB1 = ThisWorkbook Set ws1 = WB1.Worksheets("Source") last = ws1.Cells(Rows.Count, "X").End(xlUp).Row i = 2 Do Until Sheets("Source").Cells(i, 1) = "" x = Left(Sheets("Source").Cells(i, 6), 3) y = Left(Sheets("Source").Cells(i, 23), 7) If x = "611" Or y = "INITIAL" Then Sheets("Source").Cells(i, 25) = "INITIAL" Else ws1.Range("Y2:Y" & last).Formula = "=VLOOKUP(A:A,'Assignment Reference'!$C:$E,3,FALSE)" End If i = i + 1 Loop”会导致执行速度变慢。我想知道是否有办法让我的代码运行得更快。我只使用do直到循环，因为我很满意。感谢

time_precision

Answer 1

如何提高Excel的VBA代码的性能有很多种可能的方法。你最好读一些关于它的文章：

编辑：正如 Bond 所建议的，我在这里是我在VBA代码中所做的，以提高执行性能：

Option Explicit

Dim screenUpdating As Boolean
Dim calculation As XlCalculation
Dim enableEvents As Boolean
Dim displayPageBreaks As Boolean



' Freezes Excel into its current state to improve
' performance during executing macro code. Be sure
' to call DoEvents occasionally during execution to
' prevent completly freezing the Excel window.
' Call this routine before all other code but after
' setting up proper exception handling.
Public Sub freezeSystem()
    'Save Excel configuration to reset later
    screenUpdating = Application.screenUpdating
    calculation = Application.calculation
    enableEvents = Application.enableEvents
    displayPageBreaks = ActiveSheet.displayPageBreaks

    'Turn off some Excel functionality so your code runs faster
    Application.screenUpdating = False
    Application.calculation = xlCalculationManual
    Application.enableEvents = False
    ActiveSheet.displayPageBreaks = False 'Note this is a sheet-level setting, but only necessary for ActiveSheet if code do not change the ActiveSheet
End Sub




' Unfreezes Excel and resets it into the configuration it had
' before the freezeSystem() was executed.
' Call this routine at the end of the macro code and also during
' the cleanup of exception handling.
Public Sub defreezeSystem()
    ' Reset Excel configuration into previous state
    Application.screenUpdating = screenUpdating
    Application.calculation = calculation
    Application.enableEvents = enableEvents
    ActiveSheet.displayPageBreaks = displayPageBreaks 'Note this is a sheet-level setting, but only necessary for ActiveSheet if code do not change the ActiveSheet

    ' Perform recalculation of all formulas
    Application.CalculateFullRebuild
End Sub




' This routine is intended to update the Excel window
' while executing macro code in controlled manner if
' necessary. Be aware that calling this function too
' often will drastically reduce the execution performance.
Public Sub updateSystem()
    If Application.screenUpdating = False Then
        Application.screenUpdating = True
        Application.CalculateFullRebuild
        Application.screenUpdating = False
    Else
        Application.CalculateFullRebuild
    End If
End Sub

在开头或您的代码中调用freezeSystem()以提高执行期间的性能。在代码末尾调用defreezeSystem()，并在必要时在异常处理期间进行清理。

我是这样做的：

Sub entryPoint()
    On Error GoTo entryPointErrorHandler    ' set up exception handling
    freezeSystem
    [your regular code goes here]

entryPointCleanUp:                          ' clean up from exception and normal operation
    [your cleanup code goes here]
    defreezeSystem
    Exit Sub

entryPointErrorHandler:                     ' exception handling
    [your exception handling code goes here]
    GoTo entryPointCleanUp                  ' jump to clean up code

End Sub

Answer 2

加快速度的一种方法是告诉Excel不要为更新屏幕或计算单元格而烦恼。在循环之前关闭它们并在以下之后打开它们：

'***** Before loop
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual

'***** After loop
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic

Answer 3

尝试使用您已设置的参考。例如：而不是

Do Until Sheets("Source").Cells(i, 1) = ""
x = Left(Sheets("Source").Cells(i, 6), 3)
y = Left(Sheets("Source").Cells(i, 23), 7)

使用

Do Until Sheets("Source").Cells(i, 1) = ""
   x = Left(ws1.Cells(i, 6), 3)
   y = Left(ws1.Cells(i, 23), 7)

我也会尽量避免VLOOKUP，这非常慢。如果您只需检查某个范围内的值是否存在，COUNTIF要快得多。

另一种方法是代替do-until循环来使代码执行得更快

3 个答案: