批量选中所有奇数列(Excel VBA)

Sub 选择奇数列()
Dim a As Range
Dim i, n
i = Application.CountA(Rows(1))
'i用第一行判断内容有多少列
For n = 1 To i Step 2 '步长2保证奇数全部union
If a Is Nothing Then
Set a = Columns(1)
Else
Set a = Union(a, Columns(n))
End If
Next
a.Select
End Sub