excel-vba Common Mistakes ActiveWorkbook vs. ThisWorkbook
Example
ActiveWorkbook and ThisWorkbook sometimes get used interchangeably by new users of VBA without fully understanding which each object relates to, this can cause undesired behaviour at run-time. Both of these objects belong to the Application Object
The ActiveWorkbook object refers to the workbook that is currently in the top-most view of the Excel application object at the time of execution. (e.g. The workbook that you can see and interact with at the point when this object is referenced)
Sub ActiveWorkbookExample()
'// Let's assume that 'Other Workbook.xlsx' has "Bar" written in A1.
ActiveWorkbook.ActiveSheet.Range("A1").Value = "Foo"
Debug.Print ActiveWorkbook.ActiveSheet.Range("A1").Value '// Prints "Foo"
Workbooks.Open("C:\Users\BloggsJ\Other Workbook.xlsx")
Debug.Print ActiveWorkbook.ActiveSheet.Range("A1").Value '// Prints "Bar"
Workbooks.Add 1
Debug.Print ActiveWorkbook.ActiveSheet.Range("A1").Value '// Prints nothing
End Sub
The ThisWorkbook object refers to the workbook in which the code belongs to at the time it is being executed.
Sub ThisWorkbookExample()
'// Let's assume to begin that this code is in the same workbook that is currently active
ActiveWorkbook.Sheet1.Range("A1").Value = "Foo"
Workbooks.Add 1
ActiveWorkbook.ActiveSheet.Range("A1").Value = "Bar"
Debug.Print ActiveWorkbook.ActiveSheet.Range("A1").Value '// Prints "Bar"
Debug.Print ThisWorkbook.Sheet1.Range("A1").Value '// Prints "Foo"
End Sub
