//app.json 添加 (json 文件不能有注释)"navigationStyle": "custom"
<view class="app"><view class="nav-top" style="padding-top: {{statusBarHeight }}px; background-color: rgb(45, 183, 245, {{num}})"><view class="nav-top-img-view" bindtap="onBack"><image src="../../img/icons/arrow-left-bold.png"></image></view><view class="nav-top-title">标题</view><view class="nav-top-img-view"></view></view><view class="list" style="padding-top: {{statusBarHeight + 45 }}px"><view class="list-item">1</view><view class="list-item">2</view><view class="list-item">3</view><view class="list-item">4</view><view class="list-item">5</view></view></view>
.nav-top{position: fixed;top: 0;left: 0;height: 45px;width: 100%;/* opacity: .5; */display: flex;flex-direction: row;}.nav-top-img-view {height: 45px;width: 45px;}.nav-top image {height: 20px;width: 20px;margin: 12.5px;}.nav-top-title {font-weight: bolder;text-align: center;line-height: 45px;flex: 1;}.list {}.list-item {height: 50vh;margin: 20rpx;background-color: #ededed;}
Page({data: {statusBarHeight: wx.getSystemInfoSync()['statusBarHeight'],num: 0},onPageScroll (e) {if (e.scrollTop < 500) {this.setData({num: e.scrollTop / 500})} else {this.setData({num: 1})}},})
小程序官方并不推荐频繁 setData不过 iPhone 6s 上体验很流畅，所以暂时忽略，有更好的方案再更新
