/// <summary>
        /// 读取用户指定WorkSheet的数据，作为DataTable输出
        /// </summary>
        /// <param name="excelFilePath">被读取的Excel文档路径</param>
        /// <param name="HeadRowAsColumnCaption">是否将Excel第一行作为DataTable表头输出</param>
        /// <param name="workSheetName">被读取的WorkSheet名称</param>
        /// <returns></returns>
        public static System.Data.DataTable ReadExcelToDataTable(string excelFilePath, bool HeadRowAsColumnCaption, string workSheetName)
        {
            System.Data.DataTable dataTable = new System.Data.DataTable();

            System.Data.OleDb.OleDbConnection conn = GetConnection(excelFilePath, HeadRowAsColumnCaption);
            if (conn != null)
            {
                conn.Open();
                string strSql = "select * from [" + workSheetName + "$]";
                System.Data.OleDb.OleDbDataAdapter sda = new System.Data.OleDb.OleDbDataAdapter(strSql, conn);
                dataTable.TableName = workSheetName;
                sda.Fill(dataTable);
                conn.Close();
            }
            return dataTable;
        }