C#操作xls

public DataSet getData(string p)
        {
            //判断文件后缀
            var path = p;
            string fileSuffix = System.IO.Path.GetExtension(path);
            if (string.IsNullOrEmpty(fileSuffix))
                return null;
            using (DataSet ds = new DataSet())
            {
                //判断Excel文件是2003版本还是2007版本
                string connString = "";
                if (fileSuffix == ".xls")
                    connString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + path + ";" + ";Extended Properties="Excel 8.0;HDR=YES;IMEX=1"";
                else
                    connString = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + path + ";" + ";Extended Properties="Excel 12.0;HDR=YES;IMEX=1"";
                //读取文件
                string sql_select = " SELECT * FROM [Sheet1$]";
                using (OleDbConnection conn = new OleDbConnection(connString))
                using (OleDbDataAdapter cmd = new OleDbDataAdapter(sql_select, conn))
                {
                    conn.Open();
                    cmd.Fill(ds);
                }
                if (ds == null || ds.Tables.Count <= 0) return null;
                return ds;
            }
        }