利用正则表达式将html网页数据变成Web Service[4]

            using( webclient client = new webclient() )
            {
                byte[] buffer = client.downloaddata( url );
                string str = encoding.getencoding("gb2312").getstring( buffer, 0, buffer.length );
                return str;
            }
        }
        private xmldatadocument getxmldoc()
        {
            string webcontent = getwebcontent("http://www.bank-of-china.com/info/whjrpj.html");

            //    prepair for dataset
            dataset ds = new dataset("exchange");
            datatable dt = new datatable("foreignexchange");
            ds.tables.add( dt );
            dt.columns.add( "currency", typeof(string) );
            dt.columns.add( "bankbuytt", typeof(double) );
            dt.columns.add( "bankbuynotes", typeof(double) );
            dt.columns.add( "banksell", typeof(double) );