$string = '<img alt="Peachtree St Apartment 2" data-url="http://i.oodleimg.com/item/3472578127t_1m_condos,_townhouses_&_apts_for_sale_in_johnson_city_tn/?1377909664" src="http://i.oodleimg.com/a/animate/spinner-small.gif" class="lazyload-image">';
我想在 PHP 中提取 data-url 参数。