在Workbook_open上创建并分配变量，然后将其传递给Worksheet_change

Question

So I have a Workbook_open sub that creates Long variables when workbook is opened:

Private Sub Workbook_open()
  MsgBox ("Workbook opened")

  Dim i As Long
  i = 68 
End Sub

How would I pass the i value to a Worksheet_change sub for a particular worksheet?

Answer 1

Dim i inside a procedure scope makes i a local variable; it's only accessible from within the procedure it's declared in.

The idea of passing i to another procedure is very sound: it means you intend to keep variable scopes as tight as possible, and that's a very very good thing.

But in this case it's too tight, because the parameters of an event handler are provided by the event source: you need to "promote" that local variable up one scope level.

And the next tightest scope level is module scope .

You can use the Dim keyword at module level, but for consistency's sake I'd recommend using the keyword Private instead. So in the same module , declare your module-level variable:

Option Explicit
Private i As Long

Private Sub Workbook_open()
  MsgBox "Workbook opened"
  i = 68 
End Sub

If you want to expose that variable's value beyond this module, you can expose an accessor for it:

Option Explicit
Private i As Long

Private Sub Workbook_open()
  MsgBox "Workbook opened"
  i = 68 
End Sub

Public Property Get MyValue() As Long
'invoked when MyValue is on the right-hand side expression of an assignment,
'e.g. foo = ThisWorkbook.MyValue
    MyValue = i
End Property

Now the Sheet1 module's Worksheet_Change handler can read it:

Private Sub Worksheet_Change(ByVal Target As Range)
    MsgBox ThisWorkbook.MyValue
End sub

But it can't write to it, because the property is "get-only". If everyone everywhere needs to be able to read/write to it, then you might as well make it a global variable , or expose a mutator for it:

Option Explicit
Private i As Long

Private Sub Workbook_open()
  MsgBox "Workbook opened"
  i = 68 
End Sub

Public Property Get MyValue() As Long
'invoked when MyValue is on the right-hand side expression of an assignment,
'e.g. foo = ThisWorkbook.MyValue
    MyValue = i
End Property

Public Property Let MyValue(ByVal value As Long)
'invoked when MyValue is on the left-hand side of an assignment,
'e.g. ThisWorkbook.MyValue = 42; the 'value' parameter is the result of the RHS expression
    i = value
End Property

Answer 2

For that, declare i as a Public Variable on a Standard Module like Module1 and then you can access the value of i in Sheet Change Event if it is initialized during Workbook Open Event .

On Standard Module:

Public i As Long

On ThisWorkbook Module:

Private Sub Workbook_open()
  MsgBox ("Workbook opened")
  i = 68
End Sub