微信小程序实现双层嵌套菜单栏

最近在做的项目有这样一个需求,也不太好描述,就是有两个顶部菜单栏,每个二级菜单栏的item都有自己页面,每个页面都可以通过左右滑动来切换,第一个想到的实现方法就是双层swiper嵌套,但想要达到一个联动的效果还是有一点点复杂,去网上找了一圈也没结果只好自己来搞一下了

先贴一下效果图

1.先把第一层swiper框架搭好,需要能通过滑动和点击切换页面,基本方法可百度

2.在第一层的<swiper-item>中嵌入第二层的<swiper>,方法照旧

3.基本功能能实现,问题也来了,如何实现第二层的<swiper-item>滑到尽头时第一层的<swiper>能随之改变,基本实现思路是通过绑定swiper组件的回调方法bindtransition获取swiper-item的位移数据,但是回调的数据并没有swiper-item的下标,所以无法判定当前滑动的swiper-item是否在边缘,所以只能自己动脑筋了,方法就是在边缘的swiper-item容器内加一个充满容器的view,并且绑定touch的相关方法,在方法内设置是否越级翻页的flag为true,当然这个flag在js中默认定义为false,有了这个flag再加上bindtransition的回调偏移量就能够实现越级翻页了

4.思路上是没问题的,但是写完会发现有许许多多小bug,一不小心就会崩溃的那种,最后经过不断的调整和测试,崩溃是不会了,滑动也挺顺畅的,下面贴完整代码

wxml:

<view class="contain">   <view class='tabbar'>     <view class="tabbar_item {{swipeIndex==0 ? 'on' : ''}}" data-current='0' bindtap="swichNav">       <view>item1</view>     </view>     <view class="tabbar_item {{swipeIndex==1 ? 'on' : ''}}" data-current='1' bindtap="swichNav">       <view>item2</view>     </view>     <view class="tabbar_item {{swipeIndex==2 ? 'on' : ''}}" data-current='2' bindtap="swichNav">       <view>item3</view>     </view>   </view>   <swiper current="{{currentTab}}" class="swiper-box" duration="300" bindchange="bindChange" style="overflow-y:hidden">     <swiper-item>       <view class="swiper1_top">         <view class="swiper1_top_item {{itemIndex1==0 ? 'on' : ''}}" data-current1='0' bindtap="itemSwich1">child_item1.1</view>         <view class="swiper1_top_item {{itemIndex1==1 ? 'on' : ''}}" data-current1='1' bindtap="itemSwich1">child_item1.2</view>       </view>       <swiper current="{{itemCurrent1}}" duration="300" bindchange="swiperItemChange1" bindtransition="swiperTrans">         <swiper-item>           child_item1.1的页面         </swiper-item>         <swiper-item>           <view style="width:100vw;height:100%" bindtouchmove="itemTouchRightMove" bindtouchend="itemTouchRightEnd"  bindtouchcancel="itemTouchRightEnd">child_item1.2的页面</view>         </swiper-item>       </swiper>     </swiper-item>     <swiper-item>       <view class="swiper1_top">         <view class="swiper1_top_item {{itemIndex2==0 ? 'on' : ''}}" data-current2='0' bindtap="itemSwich2">child_item2.1</view>         <view class="swiper1_top_item {{itemIndex2==1 ? 'on' : ''}}" data-current2='1' bindtap="itemSwich2">child_item2.2</view>         <view class="swiper1_top_item {{itemIndex2==2 ? 'on' : ''}}" data-current2='2' bindtap="itemSwich2">child_item2.3</view>       </view>       <swiper current="{{itemCurrent2}}" duration="300" bindchange="swiperItemChange2" bindtransition="swiperTrans">         <swiper-item style="width:100vw;height:100%" bindtouchmove="itemTouchLeftMove" bindtouchend="itemTouchLeftEnd" bindtouchcancel="itemTouchLeftEnd">           child_item2.1的页面         </swiper-item>         <swiper-item>           <view style="width:100vw;height:100%" >child_item2.2的页面</view>         </swiper-item>         <swiper-item>           <view style="width:100vw;height:100%" bindtouchmove="itemTouchRightMove" bindtouchend="itemTouchRightEnd" bindtouchcancel="itemTouchRightEnd">child_item2.3的页面</view>         </swiper-item>       </swiper>     </swiper-item>      <swiper-item>       <view class="swiper1_top">         <view class="swiper1_top_item {{itemIndex3==0 ? 'on' : ''}}" data-current3='0' bindtap="itemSwich3">child_item3.1</view>         <view class="swiper1_top_item {{itemIndex3==1 ? 'on' : ''}}" data-current3='1' bindtap="itemSwich3">child_item3.2</view>         <view class="swiper1_top_item {{itemIndex3==2 ? 'on' : ''}}" data-current3='2' bindtap="itemSwich3">child_item3.3</view>       </view>       <swiper current="{{itemCurrent3}}" duration="300" bindchange="swiperItemChange3" bindtransition="swiperTrans">         <swiper-item style="width:100vw;height:100%" bindtouchmove="itemTouchLeftMove" bindtouchend="itemTouchLeftEnd" bindtouchcancel="itemTouchLeftEnd">           child_item3.1的页面         </swiper-item>         <swiper-item>           <view style="width:100vw;height:100%" >child_item3.2的页面</view>         </swiper-item>         <swiper-item>           <view style="width:100vw;height:100%" >child_item3.3的页面</view>         </swiper-item>       </swiper>     </swiper-item>   </swiper> </view>

wxss:

page {   font-size: 3.5vw;   height: 100%;   width: 100%;   display: flex;   flex-direction: column; } swiper{   height: 100%;   width: 100%; } .contain {   display: flex;   flex-direction: column;   flex: 1;   height: 0; } .tabbar {   height: 5vw;   width: 100vw;   display: flex;   flex-direction: row;   justify-content: space-around;   border-bottom: 3px #dbdbdb solid;   padding-bottom: 2vw; } .tabbar_item {   display: flex;   flex: 1;   flex-direction: column;   align-items: center; } .on {   color: coral; } .swiper-box {   display: flex;   flex-direction: column;   flex: 1;   height: 0;   width: 100%;   overflow-x: hidden;   overflow-y: scroll; } .swiper1_top {   width: 100vw;   display: flex;   margin-left: 2vw;   flex-direction: row;   font-size: 4vw;   align-items: center;   background-color: white; } .swiper1_top_item {   flex: 1;   display: flex;   justify-content: center;   align-items: center;   padding: 2.5vw 0; } .swiper1_contain {   width: 100vw;   height: 100%;   display: flex;   flex-direction: column;   align-items: center; } .swiper1_item {   margin-bottom: 3vw;   width: 94vw; } .dir_row {   display: flex;   flex-direction: row; }

js:

Page({   /**    * 页面的初始数据    */   data: {     currentTab: 0,     swipeIndex: 0,     itemCurrent1: 0,     itemIndex1: 0,     itemCurrent2: 0,     itemIndex2: 0,     itemCurrent3: 0,     itemIndex3: 0,     flag1: false,     flag2: false,     flag3: true   },   /**     * 滑动切换tab     */   bindChange: function(e) {     console.log('debugbindcange')     var that = this;     that.setData({       swipeIndex: e.detail.current     });   },   swiperItemChange1: function(e) {     var that = this;     that.setData({       itemIndex1: e.detail.current     });   },   swiperItemChange2: function(e) {     var that = this;     that.setData({       itemIndex2: e.detail.current     });   },   swiperItemChange3: function(e) {     var that = this;     that.setData({       itemIndex3: e.detail.current     });   },   /**     * 点击tab切换     */   swichNav: function(e) {     var that = this;     if (this.data.swipeIndex === e.currentTarget.dataset.current) {       return false;     } else {       that.setData({         currentTab: e.currentTarget.dataset.current       })     }   },   itemSwich1: function(e) {     var that = this;     if (this.data.itemIndex1 === e.currentTarget.dataset.current1) {       return false;     } else {       that.setData({         itemIndex1: e.currentTarget.dataset.current1,         itemCurrent1: e.currentTarget.dataset.current1       })     }   },   itemSwich2: function(e) {     var that = this;     console.log(e)     if (this.data.itemIndex2 === e.currentTarget.dataset.current2) {       return false;     } else {       that.setData({         itemIndex2: e.currentTarget.dataset.current2,         itemCurrent2: e.currentTarget.dataset.current2       })     }   },   itemSwich3: function(e) {     var that = this;     if (this.data.itemIndex3 === e.currentTarget.dataset.current3) {       return false;     } else {       that.setData({         itemIndex3: e.currentTarget.dataset.current3,         itemCurrent3: e.currentTarget.dataset.current3       })     }   },   /**    * 滑动item绑定事件    */   swiperTrans: function(e) {     var that = this;     var dx = e.detail.dx     if (this.data.flag3 && (this.data.flag2) && (dx >= 50) && (dx < 100)) {       console.log('debug')       that.data.flag3 = false       this.setData({         currentTab: that.data.swipeIndex + 1,       })     }     if (this.data.flag3 && (this.data.flag1) && (dx <= -50) && (dx > -100)) {       that.data.flag3 = false       this.setData({         currentTab: that.data.swipeIndex - 1,       })     }   },   itemTouchLeftMove: function(e) {     this.data.flag1 = true;   },   itemTouchLeftEnd: function(e) {     this.data.flag1 = false;     this.data.flag3 = true;   },   itemTouchRightMove: function(e) {     this.data.flag2 = true;   },   itemTouchRightEnd: function(e) {     this.data.flag2 = false;     this.data.flag3 = true;   } })

json没有

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