39 lines
1.1 KiB
JavaScript
39 lines
1.1 KiB
JavaScript
|
|
if(jQuery(document).height() > jQuery(window).height() + 100) {
|
|
jQuery(".byg_scrolltop").addClass("scrolltop_show");
|
|
jQuery(".scrolltop_top").css("display","none");
|
|
}
|
|
|
|
jQuery(window).scroll(function() {
|
|
if(jQuery(window).scrollTop() < 500) {
|
|
jQuery(".scrolltop_top").css("display","none");
|
|
} else {
|
|
jQuery(".scrolltop_top").removeAttr("style","");
|
|
}
|
|
});
|
|
|
|
var new2_scroll_position = 0;
|
|
var last2_scroll_position;
|
|
var scroll_scroll_d = 0, scroll_scroll_t = 0;
|
|
window.addEventListener('scroll', function(e) {
|
|
last2_scroll_position = window.pageYOffset;
|
|
// 向下滚动
|
|
if (new2_scroll_position < last2_scroll_position) {
|
|
scroll_scroll_d = last2_scroll_position;
|
|
if (scroll_scroll_d > scroll_scroll_t + 50) {
|
|
jQuery(".byg_scrolltop").removeClass("scrolltop_show");
|
|
}
|
|
// 向上滚动
|
|
} else if (new2_scroll_position > last2_scroll_position) {
|
|
scroll_scroll_t = last2_scroll_position;
|
|
if (scroll_scroll_d > scroll_scroll_t + 50) {
|
|
jQuery(".byg_scrolltop").addClass("scrolltop_show");
|
|
}
|
|
}
|
|
new2_scroll_position = last2_scroll_position;
|
|
});
|
|
|
|
function topFunction() {
|
|
jQuery("html, body").animate({scrollTop: 0}, 500);
|
|
}
|