导航栏透明渐变效果
实现原理
- 利用position:absolute在导航下定位一个view作为背景渐变使用;
- 通过改变改view的opacity来实现透明渐变。
WXML
<!--pages/scroll/scroll.wxml-->
<view style="height:100%;position:fixed;100%;">
<scroll-view scroll-y="false" bindscroll="scroll" style="height:100%;">
<view class="page-group">
<view class="page-group-position" style="opacity:{{scrollTop / 400 > 0.9 ? 0.9 : scrollTop / 400}}"></view>
<view class="page-nav-list"><text>首页</text></view>
<view class="page-nav-list"><text>活动</text></view>
<view class="page-nav-list"><text>菜单</text></view>
<view class="page-nav-list"><text>我的</text></view>
</view>
<view class="page-banner">
banner
</view>
<view class="goods-list">
goods-list1
</view>
<view class="goods-list list2">
goods-list2
</view>
<view class="goods-list list3">
goods-list3
</view>
<view class="goods-list list4">
goods-list4
</view>
</scroll-view>
</view>WXSS
.page-banner{height: 500rpx;background-color: greenyellow;padding: 20rpx;color:#fff;padding-top: 100rpx;}
.page-group{
display: table;
width: 100%;
table-layout: fixed;
position: fixed;
top: 0;
left: 0;
z-index: 10;
}
.page-group-position{
width: 100%;
height: 100%;
position: absolute;
top: 0;
left: 0;
background-color: blueviolet;
opacity: 0;
z-index: -1;
}
.page-nav-list{
padding:30rpx 0 ;
display: table-cell;
text-align: center;
width: 100%;
color: #fff;
}
.goods-list{
height: 500rpx;
background-color: green;
padding: 20rpx;
color:#fff;
}
.list2{background-color: blue;}
.list3{background-color: yellow;}
.list4{background-color: red;}JS
Page({
data: {
scrollTop: null
},
//滚动条监听
scroll: function (e) {
this.setData({ scrollTop: e.detail.scrollTop })
},
})总结：
1. 需要scroll-view组件配合使用才能获取scrollTop;
2. scrollTop / 400 > 0.9，这里400的距离是根据需求改变，0.9是背景最后的半透明值，可以根据页面调节。