DataTable dt = ExcelHelper.ToDataTable(fileinfo.FilePath);
                 //将datatable的第二行变为列标题字段
                  DataTable dt2 = new DataTable();
                foreach (DataRow item in dt.Rows)
                {
                    foreach (var item2 in item.ItemArray)
                        dt2.Columns.Add(item2.ToString(), typeof(string));
                    break;
                }
                int k = 0;
                foreach (DataRow item in dt.Rows)
                    if (k == 0)
                    {
                        k++;
                        continue;
                    }
                    else
                        dt2.Rows.Add(item.ItemArray);