function is_appear(item){ var win_height=$(window).height(); console.log("可視高度:"+win_height); var mTop = $("#"+item).offset().top; console.log("距離文檔頂部距離:"+mTop); var sTop = $(window).scrollTop(); console.log("卷入高度"+sTop); var result = mTop - sTop; console.log("元素距離瀏覽器的高度"+result); if(result>win_height){ return false; }{ return true; } }

$(window).bind("scroll", function () {

? ? var res=is_appear("d1");

? ? console.log(res);

? });