How to improve slow macro? - excel

Question

I need to use Word Macro for automatically proofreading the documents. I have an excel file, filled in with all the wrong spelling words, and after I installed the macro to Microsoft Word, it took several minutes to finish the spelling checking for just 1 page of the Word Document.
Can I use .txt to replace the excel in order to make it faster? Or what should I improve? Below please find the code for the Macro:
Attribute VB_Name = "PR"
Option Explicit
Sub PR()
Dim Path As String
Dim objExcel As Object
Dim iCount As Integer
Dim VChar As String
Dim OChar As String
Options.AutoFormatAsYouTypeReplaceQuotes = True
Path = "D:\Macro\rplPR.xlsx"
'Highlight variant characters
With ActiveDocument
.TrackRevisions = False
.ShowRevisions = False
End With
Set objExcel = CreateObject("Excel.Application")
objExcel.Workbooks.Open Path
For iCount = 2 To 2500
Selection.HomeKey Unit:=wdStory
VChar = objExcel.ActiveWorkbook.Sheets(1).Cells(iCount, 1)
If Len(VChar) = 0 Then Exit For
Selection.HomeKey Unit:=wdStory, Extend:=wdMove
With Selection.Find
.ClearFormatting
.Replacement.ClearFormatting
.Replacement.Highlight = True
.Text = VChar
.Replacement.Text = "^&"
.Execute Replace:=wdReplaceAll
End With
Next
objExcel.ActiveWorkbook.Close
objExcel.Quit
End Sub

Answer 1

Move these lines up to above the For statement. You are setting them 2,499 times and you only need to do it once.
.ClearFormatting
.Replacement.ClearFormatting
.Replacement.Highlight = True
.Text = VChar
.Replacement.Text = "^&"
So each dot is a function call. There are 5 needless ones done 2498 times which is 12,490 function calls.
Function calls, while essential, are slow compared to other operations as there is a lot of setup.
If you didn't use with that would be an extra 12,490 function calls as well for a total of 24,980 sloww needless function calls.

Answer 2

Try the following. Do note that there is necessarily some overhead involved in starting Excel (if not already running), as well as processing the workbook. Hence, even a single-page document will encounter the same overhead there as a 100-page document.
Sub BulkFindReplace()
Application.ScreenUpdating = False
Dim xlApp As Object, xlWkBk As Object, StrWkBkNm As String, StrWkSht As String
Dim iDataRow As Long, xlFList As String, xlRList As String, i As Long
StrWkBkNm = "D:\Macro\rplPR.xlsx": StrWkSht = "Sheet1"
'Start Excel
Set xlApp = CreateObject("Excel.Application")
If xlApp Is Nothing Then
MsgBox "Can't start Excel.", vbExclamation
Exit Sub
End If
On Error GoTo 0
With xlApp
'Hide our Excel session
.Visible = False
' The file is available, so open it.
Set xlWkBk = .Workbooks.Open(StrWkBkNm, False, True)
If xlWkBk Is Nothing Then
MsgBox "Cannot open:" & vbCr & StrWkBkNm, vbExclamation
.Quit: Set xlApp = Nothing: Exit Sub
End If
' Process the workbook.
With xlWkBk
With .Worksheets(StrWkSht)
' Find the last-used row in column A.
iDataRow = .Cells(.Rows.Count, 1).End(-4162).Row ' -4162 = xlUp
' Capture the F/R data.
For i = 1 To iDataRow
' Skip over empty fields to preserve the underlying cell contents.
If Trim(.Range("A" & i)) <> vbNullString Then
xlFList = xlFList & "|" & Trim(.Range("A" & i))
xlRList = xlRList & "|" & Trim(.Range("B" & i))
End If
Next
End With
.Close False
End With
.Quit
End With
' Release Excel object memory
Set xlWkBk = Nothing: Set xlApp = Nothing
'Exit if there are no data
If xlFList = "" Then Exit Sub
'Process each word from the F/R List
With ActiveDocument.Range.Find
.ClearFormatting
.Replacement.ClearFormatting
.MatchWholeWord = True
.MatchCase = False
.Wrap = wdFindContinue
For i = 1 To UBound(Split(xlFList, "|"))
.Text = Split(xlFList, "|")(i)
.Replacement.Text = Split(xlRList, "|")(i)
.Execute Replace:=wdReplaceAll
Next
End With
Application.ScreenUpdating = True
End Sub