关于DataGrid导出到Excel时 0987 自动转换成987的问题

//给某个列加上这个属性。
private void DataGrid1_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
    if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
       IDictionaryEnumerator myEnumerator = StringOfNumtable.GetEnumerator() ;

       while( myEnumerator.MoveNext())
       {
           e.Item.Cells[(int)myEnumerator.Key].Attributes.Add ("style","vnd.ms-excel.numberformat:@");
       }

    }

}