I've heard much about the understandable abhorrence of using .Select
in Excel VBA, but am unsure of how to avoid using it. I am finding that my code would be more re-usable if I were able to use variables instead of Select
functions. However, I am not sure how to refer to things (like the ActiveCell
etc.) if not using Select
.
I have found this article on ranges and this example on the benefits of not using select but can't find anything on how?
Answer
Some examples of how to avoid select
Use Dim
'd variables
Dim rng as Range
Set
the variable to the required range. There are many ways to refer to a single-cell range
Set rng = Range("A1")
Set rng = Cells(1,1)
Set rng = Range("NamedRange")
or a multi-cell range
Set rng = Range("A1:B10")
Set rng = Range("A1", "B10")
Set rng = Range(Cells(1,1), Cells(10,2))
Set rng = Range("AnotherNamedRange")
Set rng = Range("A1").Resize(10,2)
You can use the shortcut to the Evaluate
method, but this is less efficient and should generally be avoided in production code.
Set rng = [A1]
Set rng = [A1:B10]
All the above examples refer to cells on the active sheet. Unless you specifically want to work only with the active sheet, it is better to Dim a Worksheet
variable too
Dim ws As Worksheet
Set ws = Worksheets("Sheet1")
Set rng = ws.Cells(1,1)
With ws
Set rng = .Range(.Cells(1,1), .Cells(2,10))
End With
If you do want to work with the ActiveSheet
, for clarity it's best to be explicit. But take care, as some Worksheet
methods change the active sheet.
Set rng = ActiveSheet.Range("A1")
Again, this refers to the active workbook. Unless you specifically want to work only with the ActiveWorkbook
or ThisWorkbook
, it is better to Dim a Workbook
variable too.
Dim wb As Workbook
Set wb = Application.Workbooks("Book1")
Set rng = wb.Worksheets("Sheet1").Range("A1")
If you do want to work with the ActiveWorkbook
, for clarity it's best to be explicit. But take care, as many WorkBook
methods change the active book.
Set rng = ActiveWorkbook.Worksheets("Sheet1").Range("A1")
You can also use the ThisWorkbook
object to refer to the book containing the running code.
Set rng = ThisWorkbook.Worksheets("Sheet1").Range("A1")
A common (bad) piece of code is to open a book, get some data then close again
This is bad:
Sub foo()
Dim v as Variant
Workbooks("Book1.xlsx").Sheets(1).Range("A1").Clear
Workbooks.Open("C:\Path\To\SomeClosedBook.xlsx")
v = ActiveWorkbook.Sheets(1).Range("A1").Value
Workbooks("SomeAlreadyOpenBook.xlsx").Activate
ActiveWorkbook.Sheets("SomeSheet").Range("A1").Value = v
Workbooks(2).Activate
ActiveWorkbook.Close()
End Sub
And would be better like:
Sub foo()
Dim v as Variant
Dim wb1 as Workbook
Dim wb2 as Workbook
Set wb1 = Workbooks("SomeAlreadyOpenBook.xlsx")
Set wb2 = Workbooks.Open("C:\Path\To\SomeClosedBook.xlsx")
v = wb2.Sheets("SomeSheet").Range("A1").Value
wb1.Sheets("SomeOtherSheet").Range("A1").Value = v
wb2.Close()
End Sub
Pass ranges to your Sub
s and Function
s as Range variables
Sub ClearRange(r as Range)
r.ClearContents
'....
End Sub
Sub MyMacro()
Dim rng as Range
Set rng = ThisWorkbook.Worksheets("SomeSheet").Range("A1:B10")
ClearRange rng
End Sub
You should also apply Methods (such as Find
and Copy
) to variables
Dim rng1 As Range
Dim rng2 As Range
Set rng1 = ThisWorkbook.Worksheets("SomeSheet").Range("A1:A10")
Set rng2 = ThisWorkbook.Worksheets("SomeSheet").Range("B1:B10")
rng1.Copy rng2
If you are looping over a range of cells it is often better (faster) to copy the range values to a variant array first and loop over that
Dim dat As Variant
Dim rng As Range
Dim i As Long
Set rng = ThisWorkbook.Worksheets("SomeSheet").Range("A1:A10000")
dat = rng.Value ' dat is now array (1 to 10000, 1 to 1)
for i = LBound(dat, 1) to UBound(dat, 1)
dat(i,1) = dat(i,1) * 10 'or whatever operation you need to perform
next
rng.Value = dat ' put new values back on sheet
This is a small taster for what's possible.
No comments:
Post a Comment