uniapp-微信小程序实现swiper左右滚动切换tab，上下滚动加载列表_微信小程序swipe和tab

思路：左右滑动使用swiper，上下滑动用scroll-view，swiper改变时同时改变tab并更新列表

坑点：

1. swiper高度问题，导致滑动不到最底部和最顶部

        需要手动计算，减去顶部高度和底部tabbar，并且需要同时设置padding-top和paddin-botton，否则列表显示不完整

2. 由于最开始的代码是每次切换tab后都会重新请求，导致swiper还没切换成功的过程中，显示的列表错误

        将代码改造成每一个tab下面的list都是隔离开的，原先使用了一个list维护不同tab

3. 每个tab下的list的加载完成状态也需要隔离开，否则导致tab1切换到tab2以后，tab2将控制加载完成的状态改为true后，返回tab1无法加载第2页了

4. 触底加载

        无法使用系统的触底加载了，需要使用scroll-view的自定义上拉刷新方法

5. 下拉更新

        也需要自定义，由于目前我的系统自带的还是正常的，所以还没有改造，但是体验没有scroll-view的好，因为顶部tab会遮挡下拉刷新的loading状态，后期再改造

源码：已去除不相关代码

<template>
  <view class="home-page">
    <my-tabs :tabs="tabs" :currentTab="currentTabIndex" @change="onTabChange" :top="topStyle.total" isFixed>
    </my-tabs>
    <swiper class="activity-swiper" :current="currentTabIndex" interval="500" @change="onSwiperChange"
      :style="{ height: `calc(100vh - ${listStyle.paddingTop} - ${listStyle.paddingBottom})`, paddingBottom: listStyle.paddingBottom, paddingTop: listStyle.paddingTop,}">
      <swiper-item class="activity-swiper-item" v-for="item in tabs" :key="item.key" :item-id="item.key"
        :style="{ paddingBottom: 0, paddingTop: 0 }">
        <scroll-view scroll-y class="scroll-list" @scrolltolower="onBottom" :style="{ height: '100%' }"
          :scroll-top="scrollTop" @scroll="scroll">
          <card-activity v-for="(activity, index) in listData[item.index]" :key="activity.activityId" :data="activity"
            custom-class="activity-item" @click="toActivityDetail" @share="onShare"></card-activity>
          <tui-nomore v-if="isListFinished[item.index] && listData[item.index].length > 3"></tui-nomore>
        </scroll-view>
      </swiper-item>
    </swiper>
  </view>
</template>
 
<script>
  import {
    mapState
  } from 'vuex'
  import {
    userApi,
    activityApi
  } from '@/api'
  import {
    defaultConst,
    shareTypeConst,
  } from '@/const'
  const tabObj = {
    textList: [{
        name: '我创建的',
        key: 'create',
        index: 0
      },
      {
        name: '我参与的',
        key: 'partake',
        index: 1
      },
      {
        name: '我关注的',
        key: 'follow',
        index: 2
      }
    ],
    value: {
      0: 1,
      1: 2,
      2: 3,
    }
  }
  export default {
    data() {
      return {
        currentActivity: {},
        tabs: tabObj.textList,
        currentTabIndex: 0,
        currentTabValue: 1,
        listData: {
          0: [], // create
          1: [], // partake
          2: [], // follow
        },
        // 每个tab的加载状态隔离开：解决切换到第三个tab加载完成后，返回第一个tab无法加载第二页的问题
        isListFinished: [false, false, false],
        pageIndex: 1,
        isListLoading: false,
 
        tabbarIndex: 0,
 
        scrollTop: 0,
        oldScrollTop: 0
      }
    },
    computed: {
      ...mapState(['systemInfo', 'userInfo', 'showTabBarDot']),
      topStyle() {
        const {
          statusBarHeight
        } = this.systemInfo
        const menuButtonInfo = wx.getMenuButtonBoundingClientRect()
        const navigationBarHeight = (menuButtonInfo.top - statusBarHeight) * 2 + menuButtonInfo.height
        return {
          statusBarHeight,
          navigationBarHeight,
          total: statusBarHeight + navigationBarHeight
        }
      },
      listStyle() {
        return {
          paddingTop: this.topStyle.total + 45 + 'px',
          paddingBottom: '180rpx',
        }
      }
    },
    watch: {
      currentTabIndex(value) {
        // 首次切换tab才会重新加载数据
        if (!this.listData[value].length) this.getActivityList(true)
        // this.isListFinished = false
      },
    },
    methods: {
      async getActivityList(isRefresh, params, isFirst) {
        const tab = this.currentTabIndex
        this.showNoData = false
 
        if (isRefresh) {
          this.pageIndex = defaultConst.DEFAULT_PAGE_INDEX
          this.isListFinished[this.currentTabIndex] = false
          this.listData[this.currentTabIndex] = []
        }
        const data = {
          pageIndex: this.pageIndex++,
          pageSize: defaultConst.DEFAULT_PAGE_SIZE,
          type: this.currentTabValue,
        }
        Object.keys(params || {}).map(key => {
          if (params[key]) {
            data[key] = params[key]
          }
        })
        const {
          hasNext,
          list
        } = await activityApi.getList(data)
        if (tab !== this.currentTabIndex) return
 
        if (!hasNext) {
          this.isListFinished[this.currentTabIndex] = true
        }
        if (isRefresh) {
          uni.stopPullDownRefresh()
        }
        this.listData[this.currentTabIndex].push(...list)
 
      },
      onTabChange({
        index
      }) {
        this.currentTabIndex = index
        this.currentTabValue = tabObj.value[index]
        if (!this.listData[index].length) this.skeletonShow = true
        this.goTop()
      },
      onSwiperChange(e) {
        this.currentTabIndex = e.detail.current
        this.currentTabValue = tabObj.value[e.detail.current]
        if (!this.listData[e.detail.current].length) this.skeletonShow = true
        this.goTop()
      },
      onNoticeClose() {
        this.showNotice = false;
      },
      toActivityDetail(id) {
        uni.navigateTo({
          url: `/pages/activity/detail?activityId=${id}`
        })
      },
      async onShare(activity) {
        const res = await activityApi.getDetail({
          activityId: activity.activityId
        })
        this.currentActivity = res
        this.$refs.shareActivity.share()
      },
      toCreate() {
        uni.navigateTo({
          url: '/pages/activity/create'
        })
      },
      onBottom() {
        console.log('触底了')
        if (!this.isListFinished[this.currentTabIndex]) {
          this.getActivityList(false)
        }
      },
      scroll(e) {
        //记录scroll  位置
        this.oldScrollTop = e.detail.scrollTop
      },
      goTop(e) {
        //视图会发生重新渲染 scrollTop不会随着滚动而实时更新 所以需要手动设置 之所以不在scroll方法中设置是为了防止页面抖动
        this.scrollTop = this.oldScrollTop
        //当视图渲染结束 重新设置为0
        wx.nextTick(() => {
          this.scrollTop = 0
        });
      }
    },
 
    onLoad() {
      this.skeletonShow = true
      this.getActivityList(false)
    },
 
    onPullDownRefresh() {
      this.skeletonShow = true
      this.getActivityList(true)
    },
  }
</script>
 
<style lang="scss" scoped>
  .activity-swiper {
 
    &-item {
      box-sizing: border-box;
      padding-left: 20rpx;
      padding-right: 20rpx;
    }
 
    /deep/ .activity-item {
      margin-top: 20rpx;
    }
  }
 
  .text-link {
    color: $text-link;
  }
 
  .list-no-data-text {
    color: $text-3;
  }
</style>