How to lock entire rows based on a certain word in a column without using Table in dataset - vba

Question

I am aiming to lock entire rows where the word "Done" appears in a specific column. My code below achieves what I seek but it takes 18 seconds to compute (too long). Is there a faster/more efficient coding alternative?
There is an existing question on StackOverflow similar to this (found here) but my data does not exist in defined tables (this won't change), so I don't know how to adapt the suggestion there.
Private Sub Lock_Rows(ByVal Target As Range)
Dim DestSh As Worksheet
Dim lastrow As Long
Dim i As Long ' Integer
Set DestSh = Worksheets(8) 'Data tab for Item 1
With DestSh
'finds the last row with data on B column, B column has dates
lastrow = .Range("B" & .Rows.Count).End(xlUp).Row
'parse all rows
For i = 26 To lastrow 'rows of data begin at row 26
'if your conditions are met
If .Cells(i, "Z").Value = "Done" Then
.Cells(i, "Z").EntireRow.Cells.Locked = True 'lock the row
Else
.Cells(i, "Z").EntireRow.Cells.Locked = False 'leave rows unlocked
End If
Next i
.Protect UserInterfaceOnly:=True
End With
Set DestSh = Nothing
End Sub

Answer 1

The Lock / Unlock operations om individual rows are quite slow. Better to build a range reference to Lock / Unlock and do that operation in on go at the end.
Something like
Private Sub Lock_Rows(ByVal Target As Range)
Dim DestSh As Worksheet
Dim lastrow As Long
Dim i As Long ' Integer
Dim rLock As Range, rUnlock As Range
Set DestSh = Worksheets(8) 'Data tab for Item 1
With DestSh
'finds the last row with data on B column, B column has dates
lastrow = .Range("B" & .Rows.Count).End(xlUp).Row
'parse all rows
For i = 26 To lastrow 'rows of data begin at row 26
'if your conditions are met
If .Cells(i, "Z").Value = "Done" Then
If rLock Is Nothing Then
Set rLock = .Cells(i, "Z").EntireRow
Else
Set rLock = Application.Union(rLock, .Cells(i, "Z").EntireRow)
End If
Else
If rUnlock Is Nothing Then
Set rUnlock = .Cells(i, "Z").EntireRow
Else
Set rUnlock = Application.Union(rUnlock, .Cells(i, "Z").EntireRow)
End If
End If
Next i
If Not rLock Is Nothing Then rLock.Locked = True
If Not rUnlock Is Nothing Then rUnlock.Locked = False
.Protect UserInterfaceOnly:=True
End With
Set DestSh = Nothing
End Sub
It will be faster still you could incorporate use of Variant Arrays on the loop
On my hardware it takes about 6 s to process 500,000 rows

Answer 2

Try with this solution which seems to be much faster than original one:
Private Sub Lock_Rows_new(ByVal Target As Range)
Debug.Print "s:" & Timer
Dim DestSh As Worksheet
Dim lastrow As Long
Dim i As Long ' Integer
Set DestSh = Worksheets(8) 'Data tab for Item 1
With DestSh
'range to search
Dim firstRNGRow As Variant '!! important
firstRNGRow = 26
Dim firstRNG As Range
Set firstRNG = .Cells(firstRNGRow, "Z")
Dim lastRNG As Range
Set lastRNG = .Cells(.Range("B" & .Rows.Count).End(xlUp).Row, "Z")
'unlock all
Range(firstRNG, lastRNG).EntireRow.Cells.Locked = False
'search for first done
firstRNGRow = Application.Match("Done", Range(firstRNG, lastRNG), 0)
Do While (Not IsError(firstRNGRow))
Set firstRNG = .Cells(firstRNG.Row + firstRNGRow, "Z")
firstRNG.Offset(-1, 0).EntireRow.Cells.Locked = True 'lock the row
If firstRNG.Row > lastRNG.Row Then Exit Do
firstRNGRow = Application.Match("Done", Range(firstRNG, lastRNG), 0)
Loop
.Protect UserInterfaceOnly:=True
End With
Set DestSh = Nothing
Debug.Print "e:" & Timer
End Sub

Answer 3

Edited to add a faster solution combining Sort() and AutoFilter()
AutoFilter() can make things fast:
Private Sub Lock_Rows(ByVal Target As Range)
With Worksheets(8)
If IsEmpty(.Range("Z25")) Then .Range("Z25").Value = "xxx" ' be sure you have a column "header" for data in column Z from row 26 downwards
With .Range("Z25:Z" & .Cells(.Rows.Count, "B").End(xlUp).Row)
.EntireRow.Locked = False ' unlock all cells
.AutoFilter field:=1, Criteria1:="Done"
With Intersect(ActiveSheet.UsedRange, .EntireColumn).Resize(.Rows.Count - 1, .Columns.Count).Offset(1, 0)
If CBool(Application.Subtotal(103, .Cells)) Then .SpecialCells(xlCellTypeVisible).EntireRow.Locked = True ' lock only filtered range rows
End With
End With
If .Range("Z25").Value = "xxx" Then .Range("Z25").ClearContents ' remove any "not original" column header
End With
End Sub
if you know that cell Z25 content is always not empty then you can omit the lines:
If IsEmpty(.Range("Z25")) Then .Range("Z25").Value = "xxx"
If .Range("Z25").Value = "xxx" Then .Range("Z25").ClearContents
and if you Sort things, it's even faster:
Option Explicit
Private Sub Lock_Rows(ByVal Target As Range)
Dim dataRange As Range, sortRange As Range, lockRange As Range
With Worksheets("8") ' reference wanted sheet
Set dataRange = .Range("Z25", .Cells(.Rows.Count, "B").End(xlUp))
Set lockRange = Intersect(.Columns("Z"), dataRange)
Set sortRange = Intersect(dataRange.EntireRow, .UsedRange.Columns(.UsedRange.Columns.Count + 1)) ' reference the range in same rows as referenced one but in first "not used" column
Set dataRange = .Range(dataRange, sortRange)
End With
With sortRange
.Formula = "=ROW()" ' write rows indexes in referenced range. this will be used to sort things back
.Value = .Value ' get rid of formulas
End With
dataRange.Sort key1:=lockRange.Resize(1), order1:=xlAscending, Header:=xlYes ' sort data on columns with possible "Done" values
If IsEmpty(lockRange(1, 1)) Then lockRange(1, 1).Value = "xxx" ' remove any "not original" column header
With dataRange ' reference referenced sheet column B range in
.AutoFilter field:=lockRange.Column - Columns(1).Column, Criteria1:="Done"
With .Resize(.Rows.Count - 1, .Columns.Count).Offset(1, 0)
If CBool(Application.Subtotal(103, .Cells)) Then .SpecialCells(xlCellTypeVisible).EntireRow.Locked = True ' lock only filtered range rows
End With
.Parent.AutoFilterMode = False
.Sort key1:=sortRange.Resize(1), order1:=xlAscending, Header:=xlYes ' sort things back
sortRange.ClearContents ' delete rows index, not needed anymore
End With
If lockRange(1, 1).Value = "xxx" Then lockRange(1, 1).ClearContents ' remove any "not original" column header
End Sub
again, if you know that cell Z25 content is always not empty then you can omit the lines:
If IsEmpty(lockRange(1, 1)) Then lockRange(1, 1).Value = "xxx" ' remove any "not original" column header
If lockRange(1, 1).Value = "xxx" Then lockRange(1, 1).ClearContents ' remove any "not original" column header