H5 回到顶部按钮

//这里我用的是svg，所以代码老长了，可以把svg部分换成自己的图片什么的
$(function(){
    var obj = $('<div style="width:1.3rem;position:fixed;top:75%;right:1.6%;height:1.3rem;text-align:center;display: none;"class="Bottomsetting"><svg class="icon" style="height:1.3rem;vertical-align: middle;fill: #df6d5f;overflow: hidden;" viewBox="0 0 1026 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" p-id="22374"><path d="M517.64662 0.191659a511.920142 511.920142 0 1 0 0 1023.776398 511.920142 511.920142 0 0 0 0-1023.776398z m0 986.275197a474.418941 474.418941 0 1 1 474.355055-474.418941c0 261.933431-212.48551 474.418941-474.355055 474.418941z m0 0M667.204221 382.997785L530.10443 244.939701a15.332689 15.332689 0 0 0-10.988427-4.472034c-0.51109-0.127772-0.958293-0.319431-1.469383-0.319431a15.716006 15.716006 0 0 0-6.260848 1.34161 13.927192 13.927192 0 0 0-5.302555 3.385969L382.335643 368.431731a15.204916 15.204916 0 1 0 21.593536 21.52965l98.448639-98.193093v268.833141a15.204916 15.204916 0 1 0 30.473718 0v-269.599776l112.631376 113.39801a15.268802 15.268802 0 0 0 21.593536 0.063886 14.949371 14.949371 0 0 0 0.127773-21.465764z m18.271454-173.323268H349.689793a15.332689 15.332689 0 0 1-15.332688-15.268802c0-8.432979 6.89971-15.204916 15.332688-15.204916h335.785882a15.204916 15.204916 0 1 1 0 30.473718z m0 0M269.512609 618.418442c7.985775 0.51109 15.907664 0.958293 23.765667 0.958293h28.748791c7.985775 0 16.163209-0.447203 24.787847-1.022179v16.738185c-10.60511-0.51109-19.165861-1.022179-25.74614-1.022179v149.685373c0 13.160558-4.088717 21.146333-12.330037 23.829553a366.706804 366.706804 0 0 1-29.259881 7.730231 70.913685 70.913685 0 0 0-7.985775-23.637895c9.966248 0 17.50482-0.319431 22.743488-1.022179 5.366441-0.638862 7.985775-5.238669 7.985776-13.863306V634.134448c-13.224444 0-24.085098 0.51109-32.709736 1.022179V618.418442z m66.377764 191.019746c18.590885-3.833172 33.220825-9.263499 44.145366-15.716006a47.020245 47.020245 0 0 0 21.274106-24.340643c3.258196-9.58293 5.366441-21.082447 6.38862-34.562436 1.022179-13.671647 1.213838-27.726612 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0-8.944069-23.893439c15.907664 0 26.257229-1.788814 31.240354-5.430328s7.219141-8.496865 6.963596-14.310509c-0.51109-6.005303-3.897058-14.182737-10.541224-24.851733a163.548679 163.548679 0 0 0-22.743488-28.621019c5.302555-12.010606 12.202265-34.690208 20.890788-68.486009h-35.840159v195.236235h-19.676951c0.51109-13.991078 1.022179-29.643198 1.022179-47.531334V661.030539c0-14.62994-0.766634-29.132108-1.980472-43.634276h83.179836a2112.077861 2112.077861 0 0 1-26.832205 82.221543c11.94672 11.882834 20.763016 22.999033 26.257229 33.220825z m0 0" p-id="22375"></path></svg></div>');
    $("body").append(obj);
    $(document).scroll(function() {
        var dh=$(window).height();//网页可视区高度
        var hidtop=$(document).scrollTop();//网页被卷去的高度
        if(dh>hidtop){
            $(".Bottomsetting").fadeOut()
        }else if(dh<hidtop){
            $(".Bottomsetting").fadeIn()
        }
      });
      $(".Bottomsetting").on("click",function(){
        $('html,body').animate({scrollTop:0},500);
   })
})

复制过去，全局可用，简单粗暴，效果展示：