我目前正在努力使用 jquery 动画。它只是一个小动画来改变滚动的高度和不透明度。问题是,当我滚动时,动画运行不流畅。当我滚动很慢时,动画不会及时完成。它就像它暂停,直到我停止滚动。
jQuery:
$(window).scroll(function(){
if ($(window).scrollTop() > 0){
//$('#navigation').addClass('scroll');
$('#navigation').stop().animate({height: '92px'});
$('#navigation .bg').stop().animate({opacity : '.85'});
} else {
//$('#navigation').removeClass('scroll');
$('#navigation').stop().animate({height: '142px'});
$('#navigation .bg').stop().animate({opacity : '0'});
}
});
CSS:
#navigation {
width: 1350px;
position: fixed;
z-index: 2000;
background: -moz-linear-gradient(top, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(0,0,0,0.75)), color-stop(100%,rgba(0,0,0,0))); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, rgba(0,0,0,0.75) 0%,rgba(0,0,0,0) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, rgba(0,0,0,0.75) 0%,rgba(0,0,0,0) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, rgba(0,0,0,0.75) 0%,rgba(0,0,0,0) 100%); /* IE10+ */
background: linear-gradient(to bottom, rgba(0,0,0,0.75) 0%,rgba(0,0,0,0) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#bf000000', endColorstr='#00000000',GradientType=0 ); /* IE6-9 */
height: 142px;
}
#navigation .bg{
background: #000;
position: absolute;
width: 100%;
height: 92px;
top:0px;
left: 0px;
opacity: 0;
}
提前致谢