How to Lock Cell based on the value of the another cell and perform data validation

Question

I am very new to VBA code. Now I was assigned to make a task that validate the data in an excel sheets.

For Example in my Column A , I have a drop down menu that enable the user to make a selection between "Yes" or "No" only.

• If user selected "Yes", cells in Column B and Column C will be marked as Mandatory and cannot be blank. I want to put a validation error on this.

   **Example 1: If A1 and A30 == YES** 

  • B1 and C1, B30 and C30 are mandatory

  • Will fill a color to the mandatory cells and remove the fill color when the cells have value already

  • Throw a validation error when these cells are blank and if exceeds the number of characters required.

    Example 2: If A99 == NO

  • B99 will be locked and the user will not be allowed to enter a data on this cell. Possible that we can add a cell value as "NA" to avoid confusion

I was able to capture this using the data validation and conditional formatting. However, I cannot perform the locked functionality since as per research, I need a VBA code for this one.

Answer 1

Something like this should work.

Put it into the code module for the sheet you want to apply it to.

Private Sub worksheet_change(ByVal target As Range)

    ''''' CHECK IF THE CHANGED CELL IS IN RANGE A1:A99 (OR ANY OTHER RANGE YOU DEFINE)
    If Not Intersect(target, Range("A1:A99")) Is Nothing Then

        ''''' UNPROTECT THE SHEET
        ActiveSheet.Unprotect

        ''''' IF THE CELL CHANGED IS NOW 'YES'
        If target = "Yes" Then

            ''''' WE DEFINE HOW MANY COLUMNS TO MOVE ACROSS FROM THE CELL THAT CHANGED AND DO THE ACTIONS IN THE CODE BELOW
            ''''' SO IN THIS EXAMPLE WE'RE MOVING ACROSS 1 CELL TO B1 AND THEN 2 CELLS TO C1
            ''''' SO TO GET TO AA1 AND AB2 WE'D DO i = 26 to 27
            ''''' IF WE WANTED TO ACCESS AA1 ALL THE WAY THROUGH TO AZ1 WE'D DO i = 26 to 51
            For i = 1 To 2

                ''''' MOVE ACROSS i NUMBER OF CELLS FROM THE CELL THAT CHANGED
                With target.Offset(0, i)

                    ''''' UNLOCK THE CELL
                    .Locked = False

                    '''''SET THE CONDITIONAL FORMATTING
                    .FormatConditions.Add Type:=xlExpression, Formula1:="=ISBLANK(" & target.Offset(0, i).Address & ")"
                    With .FormatConditions(.FormatConditions.Count)
                        .SetFirstPriority
                        .Interior.ColorIndex = 37
                    End With

                End With

            ''''' INCREASE i BY 1 AND LOOP TO AFFECT THE NEXT CELL
            Next i

        ''''' IF THE CELL CHANGED IS NOW 'NO'
        ElseIf target = "No" Then

            ''''' WE DEFINE HOW MANY COLUMNS TO MOVE ACROSS FROM THE CELL THAT CHANGED AND DO THE ACTIONS IN THE CODE BELOW
            For i = 1 To 2

                ''''' MOVE ACROSS i NUMBER OF CELLS FROM THE CELL THAT CHANGED
                With target.Offset(0, i)

                    ''''' SET THE CELL VALUE TO BLANK
                    .Value = ""

                    ''''' LOCK THE CELL
                    .Locked = True

                    ''''' REMOVE THE CONDITIONAL FORMATTING
                    .FormatConditions.Delete

                        ''''' ADD NEW CONDITIONAL FORMATTING HERE IF REQUIRED

                End With

            ''''' INCREASE i BY 1 AND LOOP TO AFFECT THE NEXT CELL
            Next i

        End If

        '''''PROTECT THE SHEET
        ActiveSheet.Protect

    End If

End Sub

Be sure to set locked to false in your A column where the drop down lists are or users won't be able to change the drop down value while the sheet is locked.