主题：自定路径汇总数据怎么报错

Dim dlg As New OpenFileDialog
dlg.MultiSelect = True
dlg.Filter= "Excel文件|*.xls"
If dlg.ShowDialog = DialogResult.OK Then
   Dim Book As New XLS.Book(dlg.FileName)
For Each Sheet As XLS.Sheet In Book.Sheets
    Output.Show(Sheet.name)
    For h As Integer = 0 To Sheet.Rows.count -1
        For l As Integer = 0 To Sheet.cols.count -1
            Tables("学籍").rows(h)(l) =  Tables("学籍").rows(h)(l) & Sheet(h,l).Value
        Next
    Next
Next

End If