using System.Data;
using System.Data.OleDb;

 /// <summary>
        /// 读取EXCEL列数据
        /// </summary>
        /// <param name="excel_path">要读取的Excel路径</param>
        /// <param name="select_field">要读取的列名</param>
        /// <param name="sheet_name">读取sheet页</param>
        /// <param name="range">读取区域</param>
        /// <param name="where_field">条件列名</param>
        /// <param name="where_condition">条件值列表</param>
        /// <returns></returns>
        public static DataTable LoadDataFromExcel(string excel_path, string select_field, string sheet_name, string range,
            string where_field, string[] where_condition)
        {

            //定义并根据Excel版本确定链接字符串
            var file = new System.IO.FileInfo(excel_path);
            var strConn = string.Empty;
            switch (file.Extension)
            {
                case ".xls":
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + excel_path + ";Extended Properties=‘Excel 8.0;HDR=Yes;IMEX=1;‘";
                    break;
                case ".xlsx":
                    strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excel_path + ";Extended Properties=‘Excel 12.0;HDR=Yes;IMEX=1;‘";
                    break;
                default:
                    strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excel_path + ";Extended Properties=‘Excel 12.0;HDR=Yes;IMEX=1;‘";
                    break;
            }
            OleDbConnection OleConn = new OleDbConnection(strConn);
            OleConn.Open();
            //确定要读取的列名
            var strSelectCol = string.IsNullOrWhiteSpace(select_field) ? "*" : select_field.Trim();

            //拼接query语句
            var sql = "SELECT " + strSelectCol + " FROM [" + sheet_name +"$"+ range + "]";
            for (int i = 0; i < where_condition.Length; i++)
            {
                sql += (i == 0 ? " WHERE " : " or ") + where_field + " like ‘%" + where_condition[i] + "%‘";
            }
            //读取数据
            OleDbDataAdapter Oleda = new OleDbDataAdapter(sql, OleConn);
            DataSet Oleds = new DataSet();
            Oleda.Fill(Oleds, sheet_name);
            OleConn.Close();
            return Oleds.Tables[0];
        }