微信小程序实现点击返回顶层的方法

<scroll-view scroll-y style="height: 1000rpx;" scroll-top="50" enable-back-to-top="true" scroll-top="{{scrollTop.scroll_top}}" bindscroll="scrollTopFun"><block wx:for="{{sortArr}}"><template is="spL" data="{{item}}"></template></block></scroll-view> <!-- 联系客服 --><view class="findOur fliexBox"><contact-button type="default-light" size="15" session-from="weapp"></contact-button>客服</view><!-- 拨打电话 --><view class="callOur fliexBox" bindtap="call">电话</view><view class="fliexBox" style=" bottom: 150rpx; border: solid 1px green;" wx:if="{{scrollTop.goTop_show}}" catchtap="goTopFun">顶层</view>

var app = getApp();Page({data: {hidden: true,list: [],scrollTop: {scroll_top: 0,goTop_show: false},scrollHeight: 0,floorstatus:true,sortArr:[{id: 1,img: "../../images/2.jpg",title: "君御豪园住宅",introduction: "杭州不限购不限贷口住宅",money: 5000,vperson: 115,tperson: 0}],},scrollTopFun: function (e) {console.log(e.detail);if (e.detail.scrollTop > 300) {//触发gotop的显示条件 this.setData({'scrollTop.goTop_show': true});} else {this.setData({'scrollTop.goTop_show': false});}},goTopFun: function (e) {var _top = this.data.scrollTop.scroll_top;//发现设置scroll-top值不能和上一次的值一样，否则无效，所以这里加了个判断 if (_top == 0) {_top = 1;} else {_top = 0;}this.setData({'scrollTop.scroll_top': _top});},/*** 生命周期函数--监听页面加载*/onLoad: function (options) {var that = this;wx.getSystemInfo({success: function (res) {that.setData({scrollHeight: res.windowHeight});}});},}）

.fliexBox{width: 100rpx;height: 50rpx;background-color: #5db13b;color: #ffffff;text-align: center;position: fixed;right: 0rpx;bottom: 85rpx;border-radius: 20rpx 0rpx 0rpx 20rpx;font-size: 26rpx;line-height: 50rpx;opacity: .6;}.callOur{bottom: 20rpx;}contact-button{opacity: 0;position: absolute;}