How can I run VBA code each time a cell gets its value changed by a formula?

Question

How can I run a VBA function each time a cell gets its value changed by a formula?

I\'ve managed to run code when a cell gets its value changed by the user, but it d

Answer 1

Here is another way using classes. The class can store cell Initial value and cell address. On calculate event it will compare the address current value with the stored initial value. Example below is made to listen to one cell only ("A2"), but you can initiate listening to more cells in the module or change the class to work with wider ranges.

Class module called "Class1":

Public WithEvents MySheet As Worksheet
Public MyRange As Range
Public MyIniVal As Variant

Public Sub Initialize_MySheet(Sh As Worksheet, Ran As Range)
    Set MySheet = Sh
    Set MyRange = Ran
    MyIniVal = Ran.Value
End Sub
Private Sub MySheet_Calculate()

If MyRange.Value <> MyIniVal Then
    Debug.Print MyRange.Address & " was changed from " & MyIniVal & " to " & MyRange.Value
    StartClass
End If

End Sub

Initialize the class in normall module.

Dim MyClass As Class1

Sub StartClass()
Set MyClass = Nothing
Set MyClass = New Class1
MyClass.Initialize_MySheet ActiveSheet, Range("A2")
End Sub