Excel VBA 统计一个文档中所有sheet的已用行数

Sub countrownum()

    Dim i, num, rownum
    
    num = Worksheets.Count
    
    For i = 2 To num
    
        'Worksheets(i).Select
    
        rownum = WorksheetFunction.CountA(Worksheets(i).Columns("a:a"))
    
        Sheets(1).Cells(i, 5) = rownum
    
    Next
    
End Sub