Run VBA when cell changes on a different worksheet - vba

Question

I am very new at VBA, but have managed to make a code which links the header of my worksheet to a cell on another sheet.
The code runs every time I click a cell in the active worksheet. I'd like for the code to only run when a certain cell in the other worksheet changes.
"Report" has the header
"Input" has the cells which the code refers to (B18) and the cell I want the code to run on when changed (B3).
The following is the code that I already have.
Private Sub Worksheet_selectionChange(ByVal Target As Range)
ActiveSheet.PageSetup.RightHeader = "&28" & Format(Worksheets("Input").Range("b18").Text)
End Sub
Any help is much appreciated!!!

Answer 1

Not sure about your second paragraph; my understanding is that you want to monitor cell B3 on the Input worksheet, and when it changes, adjust the RightHeader of the PageSetup of worksheet Report so it reflects what's in cell B18 on the Input worksheet. If that's correct, you could put the following code behind the Input worksheet:
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Application.Intersect(Target, Me.Range("B3")) Is Nothing Then
ThisWorkbook.Worksheets("Report").PageSetup.RightHeader = "&28" & Me.Range("B18").Text
End If
End Sub
...and remove your Worksheet_SelectionChange procedure.
The idea is to monitor for changes on the Input worksheet, and act upon those involving its B3 cell.
Ideally, you'd give names to the cells above, so that your code would continue working even if you add or delete rows and columns on the Input worksheet. See Define and use names in formulas. If you were to define Inputs!B3 as MyMonitoredValue and Inputs!B18 as MyPageSetupValue, the code above would become:
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Application.Intersect(Target, Me.Range("MyMonitoredValue")) Is Nothing Then
ThisWorkbook.Worksheets("Report").PageSetup.RightHeader = "&28" & Me.Range("MyPageSetupValue").Text
End If
End Sub
...and you could re-organize the layout of the Input worksheet without worries.
Finally, instead of referring to worksheets by their tab's name (as seen from Excel), you can refer to them directly using their CodeName, as seen from the VBA editor, in the Properties window, under the worksheet's (Name) property (press Ctrl+R to show the Project Explorer, click on the worksheet under the Microsoft Excel Objects node, then press F4 to display the Properties window). You can change this value; I'd typically change it to shtReport. Yet another version of the code would then be:
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Application.Intersect(Target, Me.Range("MyMonitoredValue")) Is Nothing Then
shtReport.PageSetup.RightHeader = "&28" & Me.Range("MyPageSetupValue").Text
End If
End Sub
...which is able to withstand both changes in the Report worksheet's tab name, and reorganization of the Input worksheet.