主题：[求助]Excel表导入时，可否设定为第一张工作表

Dim xwj As  new  OpenFileDialog
xwj.Filter="Excel文件(*.xls)|*.xls"
If xwj.ShowDialog=DialogResult.Ok Then
    DataTables("比例计算").DeleteFor("")
    Dim Book As New XLS.Book(xwj.FileName)
    Dim Sheet As XLS.Sheet = Book.Sheets(0)
    Tables("比例计算").StopRedraw()
    Dim nms() As  String = {"数量","采购价","通用名","基药类别","采购类别","招标单元信息","配送企业"}
    For n As Integer = 1 To Sheet.Rows.Count -1
         Dim r As  Row = Tables("比例计算").AddNew()
         For  m As  Integer = 0 To nms.Length - 1
               r(nms(m)) = Sheet(n,m).Value
         Next
   Next
 Tables("比例计算").ResumeRedraw()
  End If

改成这样还是这个错误