上拉刷新下拉加载

<template>
    <view class="box">
     <view v-for="(item, index) in newsList" class="newslist">
    <view class="item">  
     {{item.title}}  
    </view>
     </view>
     <view class="loading">{{loadingText}}</view>
 </view>
</template>
<script>
var _self, page = 1, timer = null;
export default {
 data(){
  return{
   newsList:[],
   loadingText:'加载中...'
  }
 
 },
 //页面加载
 onLoad(){
  _self = this;
  //获取首页数据
   this.getnewsList()
    },
 
 // 下拉刷新,初始化第一页数据
 onPullDownRefresh(){
  this.getnewsList();
 },
 //页面滚动到底部的事件
 onReachBottom(){
  if(timer != null){
   clearTimeout(timer);
  }
  timer = setTimeout(function(){
 //加载更多数据
   _self.getmorenews();
  }, 1000);
 },
 methods:{
  getmorenews(){
   if(_self.loadingText != '' && _self.loadingText != '加载更多'){
    return false;
   }
   _self.loadingText = '加载中...';
   //在当前页面显示导航条加载动画。
   uni.showNavigationBarLoading();
   uni.request({
   url: 'https://ceshi2.dishait.cn/api/v1/postclass/1/post/'+page,
    method: 'GET',
    success: function(res){
     _self.loadingText = '';
     if(res.data == null){
   //在当前页面隐藏导航条加载动画。
      uni.hideNavigationBarLoading();
      _self.loadingText = '已加载全部';
      return false;
     }
     page++;
     console.log(res);
     _self.newsList = _self.newsList.concat(res.data.data.list);
     _self.loadingText = '加载更多';
     uni.hideNavigationBarLoading();
    }
   });
  },
  getnewsList(){
   page = 1;
   uni.showNavigationBarLoading();
   uni.request({
    url: `https://ceshi2.dishait.cn/api/v1/postclass/1/post/${page}`,
    method: 'GET',
    success: function(res){
  console.log(res)
     page++;
     _self.newsList = res.data.data.list;
     uni.hideNavigationBarLoading();
     uni.stopPullDownRefresh();
     _self.loadingText = '加载更多';
    }
   });
  }
 }
}
</script>
<style>
 .box{
  width: 100vw;
  height: 100vh;
 }
 .item{
  width: 100vw;
  height: 200rpx;
  border: 1rpx solid gray;
  text-align: center;
  line-height: 200rpx;
 }
 .loading{
  text-align: center;
  color: #8F8F94;
 }
</style>

pages.json加上

"enablePullDownRefresh":true

{
   "path": "pages/center/ces",
   "style": {
      "navigationBarTitleText": "学员管理",
      "enablePullDownRefresh":true
   }
},