---------------------------HTML------------------------
<view class="navbar-wrap">
<view class="column {{isFixedTop?‘fixed‘:‘‘}}" id="navbar">
<view class="block active">新品推荐</view>
<view class="block">限时优惠</view>
<view class="block">火爆热搜</view>
<view class="block">猜你喜欢</view>
</view>
<!-- 用于吸顶后 占位用的 -->
<view class="column" wx:if="{{isFixedTop}}"></view>
</view>
<view class="list {{isFixedTop?‘martop‘:‘‘}}">列表数据</view>
---------------------------CSS------------------------
.navbar-wrap {
width: 100%;
}
.navbar-wrap .column {
width: 100%;
height: 80rpx;
display: flex;
flex-direction: row;
align-items: center;
justify-content: space-around;
background: #fff;
border-bottom: solid 1px #eee;
top: 0;
left: 0;
z-index: 100;
}
.navbar-wrap .column.fixed {
position: fixed;
}
.martop{
margin-top: "吸顶对象的高度"
}
------------------------JS-------------------------
Page({
data: {
navbarInitTop: 0, //导航栏初始化距顶部的距离
isFixedTop: false, //是否固定顶部
},
/**
* 生命周期函数--监听页面加载
*/
onLoad: function(options) {
},
/**
* 生命周期函数--监听页面显示
*/
onShow: function() {
var that = this;
if (that.data.navbarInitTop == 0) {
//获取节点距离顶部的距离
wx.createSelectorQuery().select(‘#navbar‘).boundingClientRect(function(rect) {
if (rect && rect.top > 0) {
var navbarInitTop = parseInt(rect.top);
that.setData({
navbarInitTop: navbarInitTop
});
}
}).exec();
}
},
/**
* 监听页面滑动事件
*/
onPageScroll: function(e) {
var that = this;
var scrollTop = parseInt(e.scrollTop); //滚动条距离顶部高度
//判断‘滚动条‘滚动的距离 和 ‘元素在初始时‘距顶部的距离进行判断
var isSatisfy = scrollTop >= that.data.navbarInitTop ? true : false;
//为了防止不停的setData, 这儿做了一个等式判断。 只有处于吸顶的临界值才会不相等
if (that.data.isFixedTop === isSatisfy) {
return false;
}
that.setData({
isFixedTop: isSatisfy
});
}
})