微信小程式實現下拉篩選功能

<!--篩選欄-->
<view class="cxj-contents">
  <view class="cxj-menu">
    <view class="flex-view{{item.active?' active':''}}" wx:for="{{tabTxt}}" wx:key="" data-index="{{index}}"
      bindtap="filterTab" wx:key="id">
      <text class="flex_nav {{item.active?' active':''}}">{{item.text}}</text>
      <icon class="iconfont {{item.active?' iconshanglaxiala-':'iconshanglaxiala-1'}}" />
    </view>
  </view>
</view>

<!--條件選項欄-->
<view class="cxj-tab-layout"  hidden="{{!item.active}}" wx:for="{{tabTxt}}"
  wx:for-index="index1" wx:for-item="item" wx:key="id" >
  <scroll-view scroll-y class="scroll" style="height: calc(100vh - {{navH+45}}px);">
    <view class="cxj-tap-wrap">
      <view>
        <view wx:for="{{item.child}}" wx:for-item="item_child" wx:key="id" wx:for-index="index2">
          <view class="title">{{item_child.title}}:</view>
          <view class="cxj-tap-main">
            <view class="navs {{item_childtype.selected==true?'active':''}}" wx:for="{{item_child.childType}}"
              wx:for-item="item_childtype" wx:key="id" data-id="{{item_childtype.id}}" data-index="0"
              data-txt="{{item_childtype.text}}" wx:for-index="index3">
              <view bindtap="clickTabChild" data-index1="{{index1}}" data-index2="{{index2}}" data-index3="{{index3}}">{{item_childtype.text}}</view>
            </view>
          </view>
        </view>
      </view>
      <view class="select_btn">
        <button class="clear" bindtap="filterClears">清空條件</button>
        <button class="submit" bindtap="filterSubmit">確定</button>
      </view>
    </view>
    <!-- <view class="hidden" bindtap="closefilterTab"></view> -->
  </scroll-view>
</view>

@import "../../style/iconfont.wxss";
/* 篩選欄 */
.cxj-contents{
  position: sticky;
  width: 100%;
  height: 100rpx;
  z-index: 1003;
  /* box-shadow: 0px 15px 15px -15px rgba(200,200,200,0.6); */
  overflow: hidden;
  margin-top: -30rpx;
}
.cxj-menu {
  background-color: #fff; 
  width: 100%; 
  height: 100%;
  display: flex;
  flex-wrap: nowrap;
  font-size: 32rpx;
}
.cxj-menu .iconshanglaxiala-{
  color: #FF6F00
}
.cxj-menu  .iconshanglaxiala-1{
  color: #333
}

.cxj-menu .flex_nav.active {color: #FF6F00;}

.flex-view {
  -webkit-box-flex: 1;
  -webkit-flex: 1;
  -ms-flex: 1; 
  flex: 1;
  overflow: hidden; 
  display: block;
  text-align: center;
  line-height: 100rpx;
  }
.flex_nav{
  font-size: 32rpx;
  color: #333
  }
.cxj-icon {
  width: 24rpx;
  height: 24rpx;
  vertical-align: middle;
  margin-left: 5px;
}

/* 篩選內容 */
.cxj-content { 
  width: 100%;
  font-size: 28rpx;
  z-index: 1009;
}
.cxj-content-li {
  line-height: 60rpx;
  text-align: center;
}
.cxj-tab-layout {
  width: 100%;
  overflow: hidden;
  z-index: 1009;
  /* height: 100%; */
  /* padding-top: 20rpx; */
  background-color: rgba(000,000,000,.5);
  /* position: fixed; */
}
.hidden{
  background-color: rgba(000,000,000,.5);
  height: 100%;
  z-index: 9999;
  width: 100%;
}
.cxj-tab-layout  .navs.active { background: #FFE5D9 !important;}

.cxj-tap-wrap{
  padding: 0 30rpx;
  background: #fff;
  padding-bottom: 40rpx
}
.cxj-tap-main{
  display: flex;
  flex-flow: row wrap;
  justify-content: space-between;
  box-sizing: border-box;
}
.title{
  margin-bottom: 20rpx
}
.scroll{
 /* height: calc(100vh - 110px); */
}
.cxj-tab-layout .navs {
  height: 88rpx;
  line-height: 88rpx;
  text-align: center;
  font-size: 32rpx;
  font-weight: 300;
  background: #F3F3F3;
  border-radius: 6rpx;
  color: #333333;
  margin-bottom: 24rpx;
  flex: 0 0 31%;
}
.cxj-tap-main:after {
    content: ""; 
    width:31%;
}

/* 按鈕 */
.select_btn{
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.select_btn .clear{
    width: 31%;
    font-size: 30rpx;
    font-weight: 300;
    border: 1px solid #FF8751;
    border-radius: 6rpx;
    background-color: #fff;
    color: #FF8751;
    height: 88rpx;
    line-height: 54rpx;
    margin: 0;
}
.select_btn .submit{
    width: 66%;
    font-size: 30rpx;
    font-weight: 300;
    background-color: #FF8751;
    color: #fff;
    height: 88rpx;
    line-height: 60rpx;
    margin: 0;
}

// 引入資料
const tabTxtArr = require('../../utils/filtrate.js');
Page({
  /**
   * 頁面的初始資料
   */
  data: {
    tabTxt: [],
    searchParam: [],
  },

  //切換導航按鈕
  filterTab(e) {
    var that = this;
    var data = JSON.parse(JSON.stringify(that.data.tabTxt));
    var index = e.currentTarget.dataset.index;
    var newTabTxt = data.map(function (e) {
      e.active = false;
      return e;
    });
    newTabTxt[index].active = !that.data.tabTxt[index].active;
    this.setData({
      tabTxt: data
    })
  },

  // 點選導航按鈕的條件
  clickTabChild(e) {
    // console.log(e.currentTarget.dataset)
    let tabTxt = this.data.tabTxt;
    let index1 = e.currentTarget.dataset.index1;
    let index2 = e.currentTarget.dataset.index2;
    let index3 = e.currentTarget.dataset.index3;
    // console.log(index2)
    // console.log(tabTxt[index1].child[index2].childType[index3].selected);
    //1.在改變某個子按鈕之前先把該子按鈕組的所有選中狀態selected改成false，
    tabTxt[index1].child[index2].childType.forEach(e =>{
      e.selected = false
    })
    //2.之後再把當前點選的按鈕的狀態改為true
    tabTxt[index1].child[index2].childType[index3].selected = !tabTxt[index1].child[index2].childType[index3].selected;
    this.setData({
      tabTxt: tabTxt
    })
    //  console.log(tabTxt)
  },

  // 清空條件
  filterClears(e) {
    var that = this;
    let tabTxt = that.data.tabTxt;
    tabTxt.forEach(e1 => {
       console.log(e1)
      e1.child.forEach(e2 => {
        // console.log(e2)
        e2.childType.forEach(e3 => {
           console.log(e3)
           if(e1.active){
              e3.selected = false
           }
        })
      })
    })
    this.setData({
      tabTxt: tabTxt
    })
  },
  // 確定按鈕
  filterSubmit(e) {
    var that = this;
    // console.log(that.data.searchParam);
    let tabTxt = this.data.tabTxt;
    let selectedTextArr = [];
    tabTxt.forEach(e1 => {
      // console.log(e1)
      e1.active = false;  //關閉抽屜
      e1.child.forEach(e2 => {
        // console.log(e2)
        e2.childType.forEach(e3 => {
          // console.log(e3)
          if(e3.selected){
            //選中的載入在一個陣列中
            selectedTextArr.push(e3.text)
          }
        })
      })
    })
    this.setData({
      tabTxt:tabTxt
    })
    console.log(selectedTextArr)
  },
  /**
   * 生命週期函數--監聽頁面載入
   */
  onLoad: function (options) {
    let that = this;
    that.setData({
      tabTxt: tabTxtArr.tabTxt,
    })
  },
 })