VBA: How to automatically trigger macro without a button - vba

Question

I have made a macro that auto fill the formula on sheet1 whenever the row number of sheet2 is changed.
Is it possible to trigger it automatically without a button when i have any update on sheet2?
Sub Autofill()
Dim sg As Sheets
Dim Row As Long
Dim fillRow As Integer
Application.EnableEvents = False
Row = Worksheets("Sheet2").Cells(Rows.Count, 1).End(xlUp).Row
fillRow = Row - 1
Sheets("Sheet1").Select
Range("A1:E1").Select
Selection.Autofill Destination:=Range("A1:E" & fillRow), Type:=xlFillDefault
Application.EnableEvents = True
End Sub

Answer 1

You could try to create a sub like following:
Paste the following code. And change:
1) "D4" with your cells you want to "monitor"
2) Paste your macro in the line "Do things"
The problem is, your code is run everytime the focus is changed to another cell.
But you could also use Worksheet_BeforeDoubleclick if this is enough. Then every time you clicke twice the code will run
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Selection.Count = 1 Then
If Not Intersect(Target, Range("D4")) Is Nothing Then
'Do things
End If
End If
End Sub

Answer 2

Right-click on the sheet tab at the bottom of the scree, click 'view
code' then insert this following code in there.
Private Sub Worksheet_Change(ByVal Target As Range)
Dim Row As Long
Dim fillRow As Integer
This next line will exit the code if column A is not what is being
changed on the sheet. Delete it if you want the code to be triggered
by any change on any cell of the sheet.
if InRange(Target,Worksheets("Sheet2").range("A:A") = false then exit sub
Row = Worksheets("Sheet2").Cells(Rows.Count, 1).End(xlUp).Row
fillRow = Row - 1
Sheets("Sheet1").Select
Range("A1:E1").Select
Selection.Autofill Destination:=Range("A1:E" & fillRow), Type:=xlFillDefault
End Sub
Function InRange(Range1 As Range, Range2 As Range) As Boolean
InRange = Not (Application.Intersect(Range1, Range2) Is Nothing)
End Function

Answer 3

use a Worksheet.SelectionChange-Event.
in the Worksheet-VBA for sheet2 add:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Call Autofill()
End Sub
(This will be triggered if cell is changed, even if user does not leave the row, so check parameter Target.)