How to keep macro running when there are protected sheets? - vba

Question

I have protected sheets 4 with a password because there are some cells that users aren't allowed to input in those cells in sheet 4. The password is 1234.
But, I want to run my macro, and if there is an error, the cell will be highlight automatically.
My macro doesn't run and error, because the cell that I want to highlight is in protected sheet.
How to make the sheet 4 stay protected and make my macro keep running when I click the validation button?
Private Sub commandbutton1_click()
FileFormat:=xlOpenXMLWorkbookMacroEnabled, Password:=1234, WriteResPassword:=1234, _
ReadOnlyRecommended:=False, CreateBackup:=False
vehicle = Sheets("4").Range("K22")
expenditure_gasoline = Sheets("4").Range("M22")
If vehicle = true and expenditure_gasoline = 0 Then
MsgBox "it should not be empty", vbcritical
End If
If vehicle = true and expenditure_gasoline = 0 Then Sheets("4").Range("M22").Interior.ColorIndex = 3
End sub

Answer 1

Try the changes bellow (untested)
V1 - Protect the sheet from user changes, but not VBA changes UserInterfaceOnly:=True
Option Explicit
Private Sub commandbutton1_click()
Const PATH_AND_FILENAME = "C:\YourTestFile.xlsx" '<------ Update this path & file name
Dim wb As Workbook, ws As Worksheet, vehicle As Variant, expenditureGasoline As Variant
Set wb = Workbooks.Open(Filename:=PATH_AND_FILENAME, WriteResPassword:="1234", _
Password:="1234", Format:=xlOpenXMLWorkbookMacroEnabled)
Set ws = wb.Sheets("4")
ws.Protect Password:="1234", UserInterfaceOnly:=True '<--- Protect changes from UI only
Set vehicle = ws.Range("K22")
Set expenditureGasoline = ws.Range("M22")
If Not IsError(vehicle) And Not IsError(expenditureGasoline) Then
If vehicle = True And expenditureGasoline = 0 Then
ws.Range("M22").Interior.ColorIndex = 3
MsgBox "Cell M22 should not be empty", vbExclamation
End If
End If
End Sub
V2 - Unprotect before the change, and Protect back after the change
Private Sub commandbutton1_click()
Const PATH_AND_FILENAME = "C:\YourTestFile.xlsx" '<------ Update this path & file name
Dim wb As Workbook, ws As Worksheet, vehicle As Variant, expenditureGasoline As Variant
Set wb = Workbooks.Open(Filename:=PATH_AND_FILENAME, WriteResPassword:="1234", _
Password:="1234", Format:=xlOpenXMLWorkbookMacroEnabled)
Set ws = wb.Sheets("4")
Set vehicle = ws.Range("K22")
Set expenditureGasoline = ws.Range("M22")
If Not IsError(vehicle) And Not IsError(expenditureGasoline) Then
If vehicle = True And expenditureGasoline = 0 Then
ws.Unprotect "1234" '<--- Unprotect it before the change
ws.Range("M22").Interior.ColorIndex = 3
ws.Protect "1234" '<--- Protect it back, after the change
MsgBox "Cell M22 should not be empty", vbExclamation
End If
End If
End Sub