![clipboard.ejRm)想通過jquery的toggle實現點擊圖標時切換圖標方向，同時展開或收縮面板，但是通過以下代碼做，圖標時一次自動變后，就消失不見，怎么回事？$('.glyphicon-chevron-up').toggle(        function () {            $(".hideShow").css("display","table-row");            // $(this).removeClass('glyphicon-chevron-up');            // $(this).addClass('glyphicon-chevron-down');         },function(){            $(".hideShow").css("display","none");            // $(this).removeClass('glyphicon-chevron-down');            // $(this).addClass('glyphicon-chevron-up');         }     )