<div class="progress-wrap">
<svg class="progress-circle svg-content" width="100%" height="100%" viewBox="-1 -1 102 102">
<path d="M50,1 a49,49 0 0,1 0,98 a49,49 0 0,1 0,-98"/>
</svg>
</div><style>
.progress-wrap {
position: fixed;
right: 50px;
bottom: 50px;
height: 46px;
width: 46px;
cursor: pointer;
display: block;
border-radius: 50px;
box-shadow: inset 0 0 0 2px rgba(255,255,255,0.2);
z-index: 10000;
opacity: 0;
visibility: hidden;
transform: translateY(15px);
-webkit-transition: all 200ms linear;
transition: all 200ms linear;
}
.progress-wrap.active-progress {
opacity: 1;
visibility: visible;
transform: translateY(0);
}
.progress-wrap::after {
position: absolute;
font-family: 'unicons';
content: '↑';
text-align: center;
line-height: 46px;
font-size: 24px;
color: #cf3f74;
left: 0;
top: 0;
height: 46px;
width: 46px;
cursor: pointer;
display: block;
z-index: 1;
-webkit-transition: all 200ms linear;
transition: all 200ms linear;
}
.progress-wrap:hover::after {
opacity: 0;
}
.progress-wrap::before {
position: absolute;
font-family: 'unicons';
content: '↑';
text-align: center;
line-height: 46px;
font-size: 24px;
opacity: 0;
background-image: linear-gradient(298deg, var(--red), var(--yellow));
-webkit-background-clip: text;
-webkit-text-fill-color: transparent;
left: 0;
top: 0;
height: 46px;
width: 46px;
cursor: pointer;
display: block;
z-index: 2;
-webkit-transition: all 200ms linear;
transition: all 200ms linear;
}
.progress-wrap:hover::before {
opacity: 1;
}
.progress-wrap svg path {
fill: none;
}
.progress-wrap svg.progress-circle path {
stroke: #cf3f74;
stroke-width: 4;
box-sizing:border-box;
-webkit-transition: all 200ms linear;
transition: all 200ms linear;
}
</style><script type="text/javascript">
(function($) { "use strict";
//Switch dark/light
$(".switch").on('click', function () {
if ($("body").hasClass("light")) {
$("body").removeClass("light");
$(".switch").removeClass("switched");
}
else {
$("body").addClass("light");
$(".switch").addClass("switched");
}
});
$(document).ready(function(){"use strict";
//Scroll back to top
var progressPath = document.querySelector('.progress-wrap path');
var pathLength = progressPath.getTotalLength();
progressPath.style.transition = progressPath.style.WebkitTransition = 'none';
progressPath.style.strokeDasharray = pathLength + ' ' + pathLength;
progressPath.style.strokeDashoffset = pathLength;
progressPath.getBoundingClientRect();
progressPath.style.transition = progressPath.style.WebkitTransition = 'stroke-dashoffset 10ms linear';
var updateProgress = function () {
var scroll = $(window).scrollTop();
var height = $(document).height() - $(window).height();
var progress = pathLength - (scroll * pathLength / height);
progressPath.style.strokeDashoffset = progress;
}
updateProgress();
$(window).scroll(updateProgress);
var offset = 50;
var duration = 550;
jQuery(window).on('scroll', function() {
if (jQuery(this).scrollTop() > offset) {
jQuery('.progress-wrap').addClass('active-progress');
} else {
jQuery('.progress-wrap').removeClass('active-progress');
}
});
jQuery('.progress-wrap').on('click', function(event) {
event.preventDefault();
jQuery('html, body').animate({scrollTop: 0}, duration);
return false;
})
});
})(jQuery);
</script> 款式二：这款无css
var scrolltotop={
setting: {startline:100, scrollto: 0, scrollduration:1000, fadeduration:[500, 100]},
controlHTML: '<svg t="1661102410909" opacity="0.6" width="32px" height="32px" class="icon" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" p-id="1321" width="200" height="200"><path d="M512 56.889c251.364 0 455.111 203.747 455.111 455.111S763.364 967.111 512 967.111 56.889 763.364 56.889 512 260.636 56.889 512 56.889z m-179 532.11l179-179 179 179a28.444 28.444 0 0 0 40.221-40.22l-199.11-199.111a28.444 28.444 0 0 0-40.221 0l-199.111 199.11A28.444 28.444 0 0 0 332.999 589z" p-id="1322"></path></svg>', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"
controlattrs: {offsetx:60, offsety:50}, //offset of control relative to right/ bottom of window corner
anchorkeyword: 'javascript:scroll(0,0)', //Enter href value of HTML anchors on the page that should also
state: {isvisible:false, shouldvisible:false},
scrollup:function(){
if (!this.cssfixedsupport) //if control is positioned using JavaScript
this.$control.css({opacity:0}) //hide control immediately after clicking it
var dest=isNaN(this.setting.scrollto)? this.setting.scrollto : parseInt(this.setting.scrollto)
if (typeof dest=="string" && jQuery('#'+dest).length==1) //check element set by string exists
dest=jQuery('#'+dest).offset().top
else
dest=0
this.$body.animate({scrollTop: dest}, this.setting.scrollduration);
},
keepfixed:function(){
var $window=jQuery(window)
var controlx=$window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs.offsetx
var controly=$window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs.offsety
this.$control.css({left:controlx+'px', top:controly+'px'})
},
togglecontrol:function(){
var scrolltop=jQuery(window).scrollTop()
if (!this.cssfixedsupport)
this.keepfixed()
this.state.shouldvisible=(scrolltop>=this.setting.startline)? true : false
if (this.state.shouldvisible && !this.state.isvisible){
this.$control.stop().animate({opacity:0.8}, this.setting.fadeduration[0])
this.state.isvisible=true
}
else if (this.state.shouldvisible==false && this.state.isvisible){
this.$control.stop().animate({opacity:0}, this.setting.fadeduration[1])
this.state.isvisible=false
}
},
init:function(){
jQuery(document).ready(function($){
var mainobj=scrolltotop
var iebrws=document.all
mainobj.cssfixedsupport=!iebrws || iebrws && document.compatMode=="CSS1Compat" && window.XMLHttpRequest //not IE or IE7+ browsers in standards mode
mainobj.$body=(window.opera)? (document.compatMode=="CSS1Compat"? $('html') : $('body')) : $('html,body')
mainobj.$control=$('<div id="topcontrol">'+mainobj.controlHTML+'</div>')
.css({position:mainobj.cssfixedsupport? 'fixed' : 'absolute', bottom:mainobj.controlattrs.offsety, right:mainobj.controlattrs.offsetx,width:'32',height:'32',opacity:0, cursor:'pointer'})
.attr({title:'返回顶部'})
.click(function(){mainobj.scrollup(); return false})
.appendTo('body')
if (document.all && !window.XMLHttpRequest && mainobj.$control.text()!='') //loose check for IE6 and below, plus whether control contains any text
mainobj.$control.css({width:mainobj.$control.width()}) //IE6- seems to require an explicit width on a DIV containing text
mainobj.togglecontrol()
$('a[href="' + mainobj.anchorkeyword +'"]').click(function(){
mainobj.scrollup()
return false
})
$(window).bind('scroll resize', function(e){
mainobj.togglecontrol()
})
})
}
}
scrolltotop.init()