Excel VBA prevent deletion of cells but allow edit

excelvba

I have made a spreadsheet which a user can enter a postcode and a quantity into 2 cells and I have other cells doing calculations and displaying the results.

I have added some VBA to prevent anyone from deleting rows and columns but I would like to prevent deletion of any cell within a range but also allow a user to make changes to certain cells but also prevent editing of cells with formula in there.

In cell E4, the user can enter a postcode. In E6, the user can enter a quantity. These can be edited but not deleted. E8:E9 and E11:E14 are all drop down lists (validation) which hold data from lists. These can be changed using the drop down but not deleted.

L10:L14, L16, L23:L27, L29, L30:L33 can all have their data edited but not deleted.

What would the VBA for this look like? I guess it would use the Worksheet_Change() event.

Best Answer

Is this what you are trying? Users can edit cell E4 and E6 but they cannot leave it empty. I am also assuming that the cell are not empty before hand.

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
    On Error GoTo Whoa

    Application.EnableEvents = False

    If Not Intersect(Target, Range("E4")) Is Nothing Then
        If Len(Trim(Range("E4").Value)) = 0 Then Application.Undo
    ElseIf Not Intersect(Target, Range("E6")) Is Nothing Then
        If Len(Trim(Range("E6").Value)) = 0 Then Application.Undo
    End If

LetsContinue:
    Application.EnableEvents = True
    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

FOLLOWUP

Thanks that is what i want to do. What about the other ranges? Is it just a case of loads of IF THEN or can we use a CASE and loop through? – AdRock 2 mins ago

Add/Delete cell addresses from below as applicable.

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
    On Error GoTo Whoa

    Application.EnableEvents = False

    If Not Intersect(Target, Range("E4,E6,E8:E9,E11:E14,L10:L14,L16,L23:L27,L29,L30:L33")) Is Nothing Then
        If Len(Trim(Target.Value)) = 0 Then Application.Undo
    End If

LetsContinue:
    Application.EnableEvents = True
    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

How it works

I will try my best to explain how it works - please excuse my English.

The VBE will call a system function to create the password dialog box.
If user enters the right password and click OK, this function returns 1. If user enters the wrong password or click Cancel, this function returns 0.
After the dialog box is closed, the VBE checks the returned value of the system function
if this value is 1, the VBE will "think" that the password is right, hence the locked VBA project will be opened.
The code below swaps the memory of the original function used to display the password dialog with a user defined function that will always return 1 when being called.

Using the code

Please backup your files first!

Open the file(s) that contain your locked VBA Projects

Create a new xlsm file and store this code in Module1

code credited to Siwtom (nick name), a Vietnamese developer

Option Explicit

Private Const PAGE_EXECUTE_READWRITE = &H40

Private Declare Sub MoveMemory Lib "kernel32" Alias "RtlMoveMemory" _
        (Destination As Long, Source As Long, ByVal Length As Long)

Private Declare Function VirtualProtect Lib "kernel32" (lpAddress As Long, _
        ByVal dwSize As Long, ByVal flNewProtect As Long, lpflOldProtect As Long) As Long

Private Declare Function GetModuleHandleA Lib "kernel32" (ByVal lpModuleName As String) As Long

Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, _
        ByVal lpProcName As String) As Long

Private Declare Function DialogBoxParam Lib "user32" Alias "DialogBoxParamA" (ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer

Dim HookBytes(0 To 5) As Byte
Dim OriginBytes(0 To 5) As Byte
Dim pFunc As Long
Dim Flag As Boolean

Private Function GetPtr(ByVal Value As Long) As Long
    GetPtr = Value
End Function

Public Sub RecoverBytes()
    If Flag Then MoveMemory ByVal pFunc, ByVal VarPtr(OriginBytes(0)), 6
End Sub

Public Function Hook() As Boolean
    Dim TmpBytes(0 To 5) As Byte
    Dim p As Long
    Dim OriginProtect As Long

    Hook = False

    pFunc = GetProcAddress(GetModuleHandleA("user32.dll"), "DialogBoxParamA")


    If VirtualProtect(ByVal pFunc, 6, PAGE_EXECUTE_READWRITE, OriginProtect) <> 0 Then

        MoveMemory ByVal VarPtr(TmpBytes(0)), ByVal pFunc, 6
        If TmpBytes(0) <> &H68 Then

            MoveMemory ByVal VarPtr(OriginBytes(0)), ByVal pFunc, 6

            p = GetPtr(AddressOf MyDialogBoxParam)

            HookBytes(0) = &H68
            MoveMemory ByVal VarPtr(HookBytes(1)), ByVal VarPtr(p), 4
            HookBytes(5) = &HC3

            MoveMemory ByVal pFunc, ByVal VarPtr(HookBytes(0)), 6
            Flag = True
            Hook = True
        End If
    End If
End Function

Private Function MyDialogBoxParam(ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer
    If pTemplateName = 4070 Then
        MyDialogBoxParam = 1
    Else
        RecoverBytes
        MyDialogBoxParam = DialogBoxParam(hInstance, pTemplateName, _
                           hWndParent, lpDialogFunc, dwInitParam)
        Hook
    End If
End Function

Paste this code under the above code in Module1 and run it

Sub unprotected()
    If Hook Then
        MsgBox "VBA Project is unprotected!", vbInformation, "*****"
    End If
End Sub

Come back to your VBA Projects and enjoy.

Excel – How to avoid using Select in Excel VBA

Some examples of how to avoid select

Use Dim'd variables

Dim rng as Range

Set the variable to the required range. There are many ways to refer to a single-cell range:

Set rng = Range("A1")
Set rng = Cells(1, 1)
Set rng = Range("NamedRange")

Or a multi-cell range:

Set rng = Range("A1:B10")
Set rng = Range("A1", "B10")
Set rng = Range(Cells(1, 1), Cells(10, 2))
Set rng = Range("AnotherNamedRange")
Set rng = Range("A1").Resize(10, 2)

You can use the shortcut to the Evaluate method, but this is less efficient and should generally be avoided in production code.

Set rng = [A1]
Set rng = [A1:B10]

All the above examples refer to cells on the active sheet. Unless you specifically want to work only with the active sheet, it is better to Dim a Worksheet variable too:

Dim ws As Worksheet
Set ws = Worksheets("Sheet1")
Set rng = ws.Cells(1, 1)
With ws
    Set rng = .Range(.Cells(1, 1), .Cells(2, 10))
End With

If you do want to work with the ActiveSheet, for clarity it's best to be explicit. But take care, as some Worksheet methods change the active sheet.

Set rng = ActiveSheet.Range("A1")

Again, this refers to the active workbook. Unless you specifically want to work only with the ActiveWorkbook or ThisWorkbook, it is better to Dim a Workbook variable too.

Dim wb As Workbook
Set wb = Application.Workbooks("Book1")
Set rng = wb.Worksheets("Sheet1").Range("A1")

If you do want to work with the ActiveWorkbook, for clarity it's best to be explicit. But take care, as many WorkBook methods change the active book.

Set rng = ActiveWorkbook.Worksheets("Sheet1").Range("A1")

You can also use the ThisWorkbook object to refer to the book containing the running code.

Set rng = ThisWorkbook.Worksheets("Sheet1").Range("A1")

A common (bad) piece of code is to open a book, get some data then close again

This is bad:

Sub foo()
    Dim v as Variant
    Workbooks("Book1.xlsx").Sheets(1).Range("A1").Clear
    Workbooks.Open("C:\Path\To\SomeClosedBook.xlsx")
    v = ActiveWorkbook.Sheets(1).Range("A1").Value
    Workbooks("SomeAlreadyOpenBook.xlsx").Activate
    ActiveWorkbook.Sheets("SomeSheet").Range("A1").Value = v
    Workbooks(2).Activate
    ActiveWorkbook.Close()
End Sub

And it would be better like:

Sub foo()
    Dim v as Variant
    Dim wb1 as Workbook
    Dim  wb2 as Workbook
    Set wb1 = Workbooks("SomeAlreadyOpenBook.xlsx")
    Set wb2 = Workbooks.Open("C:\Path\To\SomeClosedBook.xlsx")
    v = wb2.Sheets("SomeSheet").Range("A1").Value
    wb1.Sheets("SomeOtherSheet").Range("A1").Value = v
    wb2.Close()
End Sub

Pass ranges to your Subs and Functions as Range variables:

Sub ClearRange(r as Range)
    r.ClearContents
    '....
End Sub

Sub MyMacro()
    Dim rng as Range
    Set rng = ThisWorkbook.Worksheets("SomeSheet").Range("A1:B10")
    ClearRange rng
End Sub

You should also apply Methods (such as Find and Copy) to variables:

Dim rng1 As Range
Dim rng2 As Range
Set rng1 = ThisWorkbook.Worksheets("SomeSheet").Range("A1:A10")
Set rng2 = ThisWorkbook.Worksheets("SomeSheet").Range("B1:B10")
rng1.Copy rng2

If you are looping over a range of cells it is often better (faster) to copy the range values to a variant array first and loop over that:

Dim dat As Variant
Dim rng As Range
Dim i As Long

Set rng = ThisWorkbook.Worksheets("SomeSheet").Range("A1:A10000")
dat = rng.Value  ' dat is now array (1 to 10000, 1 to 1)
for i = LBound(dat, 1) to UBound(dat, 1)
    dat(i,1) = dat(i, 1) * 10 ' Or whatever operation you need to perform
next
rng.Value = dat ' put new values back on sheet

This is a small taster for what's possible.

Best Answer

Related Solutions

Excel – way to crack the password on an Excel VBA Project

How it works

Using the code

Excel – How to avoid using Select in Excel VBA

Some examples of how to avoid select

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