求助：excel表格打开和数据读写的问题

Public Function OpenWorkFile() As Workbook

    Dim i As Integer
   
    For i = 1 To Workbooks.Count
        If Workbooks(i).Name = "work.xlsm" Then
            OpenWorkFile = Workbooks(i).Name
            Exit Function
        End If
    Next i
    OpenWorkFile = Workbooks.Open(ThisWorkbook.Path & "\work.xlsm")

End Function

运行的时候总是报错，说是 对象变量或with语句未设置。不明白~
先谢了哈~

Sub test_data()
    Dim row As Integer
    Dim col As Integer
   
    row = Workbooks("work").Sheets("outPanel").UsedRange.Rows.Count
    MsgBox row
    col = Workbooks("work").Sheets("outPanel").UsedRange.Columns.Count
    MsgBox col
   
End Sub

还有这个，我其实想得到这个工作簿中所使用的行数和列数，运行报错是下标越界，也不明白诶~

额，怎么没人理呀，表述的不清楚吗？帮帮忙啦，先谢啦~~