底部3-5个选项的底部导航栏，目前在移动端上是主流布局之一，因此腾讯官方特地做了，可以通过设置，就可以做出了一个底部的导航栏。
相关教程：微信小程序教程系列之设置栏和导航栏（7）
但是通过设置的这个底部的导航栏，功能上比较固定，它必须要设置与它对应的一个页面，而且并不能滑动。
在业务上，有时候会比较限制，并不能完全满足所需。
又例如早前有人拿着UI稿问我，这种广告轮播图的样式，在小程序能不能实现呢？
我当时没有想了下，还不是很确定，因为小程序的轮播图的那几个小点点实在比较普通，样式单一。
因此特意写了一篇自定义轮播图的文章
链接：微信小程序实战之轮播图（3）
因此自定义就有这个必要性
下面介绍这个仿Android fragment可滑动的底部导航栏如何实现
项目最终效果图：
wxml：
<swiper current="{{currentTab}}" class="swiper-box" duration="300" style="height:{{winHeight - 51}}px" bindchange="bindChange">
<!-- frag01 -->
<swiper-item>
<scroll-view class="hot-box" scroll-y="true" upper-threshold="50" lower-threshold="100" bindscrolltolower="scrolltolower">
<!-- 列表 -->
<view class="themes-list">
<view class="themes-list-box" wx:for="{{datalists}}">
<view class="themes-list-main">
<view class="themes-list-name">{{item}}</view>
</view>
</view>
</view>
</scroll-view>
</swiper-item>
<!-- grag02 -->
<swiper-item>
<scroll-view class="hot-box" scroll-y="true" upper-threshold="50" lower-threshold="100" bindscrolltolower="scrolltolower">
<!-- 列表 -->
<view class="themes-list">
<view class="themes-list-box" wx:for="{{reslists}}">
<view class="themes-list-main">
<view class="themes-list-name">{{item}}</view>
</view>
</view>
</view>
</scroll-view>
</swiper-item>
<!-- grag03 -->
<swiper-item>
<scroll-view class="hot-box" scroll-y="true" upper-threshold="50" lower-threshold="100" bindscrolltolower="scrolltolower">
<!-- 列表 -->
<view class="themes-list">
<view class="themes-list-box" wx:for="{{datalists}}">
<view class="themes-list-main">
<view class="themes-list-name">{{item}}</view>
</view>
</view>
</view>
</scroll-view>
</swiper-item>
<!-- grag02 -->
<swiper-item>
<scroll-view class="hot-box" scroll-y="true" upper-threshold="50" lower-threshold="100" bindscrolltolower="scrolltolower">
<!-- 列表 -->
<view class="themes-list">
<view class="themes-list-box" wx:for="{{reslists}}">
<view class="themes-list-main">
<view class="themes-list-name">{{item}}</view>
</view>
</view>
</view>
</scroll-view>
</swiper-item>
</swiper>
<!--tab_top-->
<view class="swiper-tab">
<view class="swiper-tab-list {{currentTab==0 ? 'active' : ''}}" data-current="0" bindtap="swichNav">
<view class="swiper-tab-img"><image class="img" src="{{currentTab==0%20?%20iconlists[0].focus:%20iconlists[0].normal}}"></image></view>
<view>frag01</view>
</view>
<view class="swiper-tab-list {{currentTab==1 ? 'active' : ''}}" data-current="1" bindtap="swichNav">
<view class="swiper-tab-img"><image class="img" src="{{currentTab==1%20?%20iconlists[1].focus:%20iconlists[1].normal}}"></image></view>
<view>frag02</view>
</view>
<view class="swiper-tab-list {{currentTab==2 ? 'active' : ''}}" data-current="2" bindtap="swichNav">
<view class="swiper-tab-img"><image class="img" src="{{currentTab==2%20?%20iconlists[2].focus:%20iconlists[2].normal}}"></image></view>
<view>frag03</view>
</view>
<view class="swiper-tab-list {{currentTab==3 ? 'active' : ''}}" data-current="3" bindtap="swichNav">
<view class="swiper-tab-img"><image class="img" src="{{currentTab==3%20?%20iconlists[3].focus:%20iconlists[3].normal}}"></image></view>
<view>frag04</view>
</view>
</view>
wxss：
.swiper-box {
display: block;
height: 100%;
width: 100%;
overflow: hidden;
}
.hot-box {
display: block;
height: 100%;
font-family: Helvetica;
}
.themes-list {
background: #fff;
display: block;
margin-bottom: 20px;
}
.themes-list-box {
display: block;
position: relative;
padding: 16px 20px;
border-bottom: 1px solid #f2f2f2;
}
.themes-list-main {
margin-left: 1px;
}
.themes-list-name {
font-size: 14px;
color: #444;
height: 20px;
line-height: 20px;
overflow: hidden;
}
.swiper-tab {
height: 50px;
background: #fff;
display: flex;
position: relative;
z-index: 2;
flex-direction: row;
justify-content: center;
align-items: center;
border-top: 1px solid #ccc;
}
.swiper-tab-list {
margin: 0 20px;
padding: 0 4px;
font-size: 28rpx;
font-family: Helvetica;
}
.active {
color: #FFCC00;
}
.swiper-tab-img {
text-align: center;
}
.img {
width:23px;
height: 23px;
}
js：
Page( {
data: {
winWidth: 0,
winHeight: 0,
currentTab: 0,
datalists : [
"习近平主持中央财经领导小组第十五次会议",
"李克强打叉的“万里审批图”成历史",
"新疆自治区举行反恐维稳誓师大会",
"朝鲜代表团抵达马来西亚处理金正男遇害案",
"习近平主持中央财经领导小组第十五次会议",
"李克强打叉的“万里审批图”成历史",
"新疆自治区举行反恐维稳誓师大会",
"砸锅卖铁！索尼是在走向毁灭 还是在奔向新生？"
],
reslists:["hello","thank you for your read","if u feel good","can u give me good？"],
iconlists:[
{normal:"../../images/wp.png",focus:"../../images/wpselect.png"},
{normal:"../../images/ss.png",focus:"../../images/ssselect.png"},
{normal:"../../images/hc.png",focus:"../../images/hcselect.png"},
{normal:"../../images/my.png",focus:"../../images/myselect.png"},
]
},
onLoad: function( options ) {
var that = this;
//获取系统信息
wx.getSystemInfo( {
success: function( res ) {
that.setData( {
winWidth: res.windowWidth,
winHeight: res.windowHeight
});
}
});
},
bindChange: function( e ) {
var that = this;
that.setData( { currentTab: e.detail.current });
},
swichNav: function( e ) {
console.log(e)
var that = this;
if( this.data.currentTab === e.currentTarget.dataset.current ) {
//点击的是同一个，则不操作
return false;
} else {
that.setData( {
currentTab: e.currentTarget.dataset.current
})
}
}
})
