微信小程序(黑马优购分类)

1.获取设备信息

 onLoad(){
      const sysInfo = uni.getSystemInfoSync()
      console.log(sysInfo);
      this.wh = sysInfo.windowHeight
    },

动态绑定高度

 <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" 
      scroll-y="true" 
      :style="{height: wh + 'px'}">

2.发起请求获取分类列表的数据

 //获取分类列表的数据
      async getCateList(){
          const {data: res} = await uni.$http.get('api/public/v1/categories')
          if(res.meta.status !== 200){
            return uni.$showMsg();
          }
          this.cateList = res.message  
      }

3.为二级分类赋值

//获取分类列表的数据
      async getCateList(){
          const {data: res} = await uni.$http.get('/api/public/v1/categories')
          if(res.meta.status !== 200){
            return uni.$showMsg();
          }
          this.cateList = res.message  
          //为二级分类赋值
          this.cateLevel2 =  res.message[0].children
          
      },
      activeChanged(i){
        this.active = i
        //重新为二级分类赋值
        this.cateLevel2 =  this.cateList[i].children
      }
    }

 <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" 
      scroll-y="true" 
      :style="{height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
            <!-- 选中项就添加active -->
            <view :class="['left-scroll-view-item',i === active? 'active' : '' ]"
              @click="activeChanged(i)"
            >
            {{item.cat_name}}</view>
        </block>
      </scroll-view>

4.点击一级分类重置滚动条

<scroll-view scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">

 activeChanged(i){
        this.active = i
        //重新为二级分类赋值
        this.cateLevel2 =  this.cateList[i].children
        
        this.scrollTop = this.scrollTop === 0? 1 : 0
      }

5.点击三级分类图片进行跳转 

<view class="cate-lv3-item" v-for="(item3,i3) in item2.children"
              :key="i3"  @click="gotoGoodsList(item3)"
              >



  //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid='+item.cat_id
        })
      }
      

分类功能完整代码

<template>
  <view>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" 
      scroll-y="true" 
      :style="{height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
            <!-- 选中项就添加active -->
            <view :class="['left-scroll-view-item',i === active? 'active' : '' ]"
              @click="activeChanged(i)"
            >
            {{item.cat_name}}</view>
        </block>
      </scroll-view>

      <!-- 右侧的滑动区域 -->
      <scroll-view scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <!-- 二级分类的标题 -->
          <view class="cate-lv2-title">
              / {{item2.cat_name}} /
          </view>
          
          <!-- 当前二级分类下的三级分类列表 -->
          <view class="cate-lv3-list">
              <!-- 三级分类的item项 -->
              <view class="cate-lv3-item" v-for="(item3,i3) in item2.children"
              :key="i3"  @click="gotoGoodsList(item3)"
              >
                <!-- 三级分类的图片 -->
                <image :src="item3.cat_icon"></image>
                <!-- 三级分类的文本 -->
                <text>{{item3.cat_name}}</text>
              </view>
              
          </view>
          
          
        </view>
      </scroll-view>
      
      
      
      
      
      
    </view>
    
    
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //当前设备可用的高度
        wh: 0,
        cateList: [],
        active: 0,
        //二级分类的列表
        cateLevel2: [],
        scrollTop: 0
      }
    },
    onLoad(){
      const sysInfo = uni.getSystemInfoSync()
      // console.log(sysInfo);
      this.wh = sysInfo.windowHeight
      this.getCateList()
      
    },
    methods: {
      //获取分类列表的数据
      async getCateList(){
          const {data: res} = await uni.$http.get('/api/public/v1/categories')
          if(res.meta.status !== 200){
            return uni.$showMsg();
          }
          this.cateList = res.message  
          //为二级分类赋值
          this.cateLevel2 =  res.message[0].children
          
      },
      activeChanged(i){
        this.active = i
        //重新为二级分类赋值
        this.cateLevel2 =  this.cateList[i].children
        
        this.scrollTop = this.scrollTop === 0? 1 : 0
      },
      //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid='+item.cat_id
        })
      }
      
    }
  }
</script>

<style lang="scss">

.scroll-view-container{
  display: flex;
  
  .left-scroll-view{
    width: 120px;
    
    .left-scroll-view-item{
      background-color: #f7f7f7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;
      //有active的标签就生效
      &.active{
        background-color: #FFF;
        position: relative;
        &::before{
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #C00000;
          position: absolute;
          top: 50%;
          left: 0;
          //在原有位置往回撤50%
          transform: translateY(-50%);
        }
      }
    }
    
  }

}

.cate-lv2-title{
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list{
  display: flex;
  // 换行
  flex-wrap: wrap;
  .cate-lv3-item{
    width: 33.3%;
    display: flex;
    //纵向布局
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    image{
      width:60px;
      height: 60px;
    }
    text{
      font-size: 12px;
    }
  }
}





</style>