uniapp实现上拉加载更多功能的全过程

data.unshift({
			name:'全部'
			}) //添加一列 ‘全部'

'use strict';
const db=uniCloud.database()//1.创建引用
exports.main = async (event, context) => {
	//event为客户端上传的参数
	const {
		name
	} = event//等同 var name=event.name
	let matchObj={}
	if (name !== '全部') {
		matchObj = {
			classify: name
		}
	} 
	const list =await db.collection('article')	//2.创建
	.aggregate()//获取聚合操作实例
	
	.match(matchObj)//筛选出classify是前端开发的
	.project({
		content:0
	})//类似.field
	.end()
	return {
		code: 200,
		msg: '数据请求成功',
		data: list.data
	}
 };

'use strict';
const db=uniCloud.database()//1.创建引用
exports.main = async (event, context) => {
	//event为客户端上传的参数
	const {
		name,
		page = 1,
		pageSize = 10
	} = event//等同 var name=event.name
	let matchObj={}
	if (name !== '全部') {
		matchObj = {
			classify: name
		}
	}
	const list =await db.collection('article')	//2.创建
	.aggregate()//获取聚合操作实例
	
	.match(matchObj)//筛选出classify是前端开发的
	.project({
		content:0
	})//类似.field
	.skip(pageSize * (page - 1))
	.limit(pageSize)//返回几条数据？
	.end()
	return {
		code: 200,
		msg: '数据请求成功',
		data: list.data
	}
 };

	<scroll-view class="list-scroll" scroll-y @scrolltolower="loadmore">

methods:{
			loadmore(){
				this.$emit('loadmore')
			}
		}

loadmore() {
				if (this.load[this.activeIndex].loading === 'noMore') return
				this.load[this.activeIndex].page++
				this.getList(this.activeIndex)
			},

getList(current) {
				if (!this.load[current]) {
					this.load[current] = {
						page: 1,
						loading: 'loading'
					}
				} //分离page 不能让他们共享一个
				
				console.log('当前的页数', this.load[current].page);
				this.$api.get_list({ //传三个参数
					name: this.tab[current].name,
					page: this.load[current].page,
					pageSize: this.pageSize
				}).then(res => {
					console.log(res);
					const {
						data
					} = res
					if (data.length === 0) {
						let oldLoad = {}
						oldLoad.loading = 'noMore'
						oldLoad.page = this.load[current].page
						this.$set(this.load, current, oldLoad)
						// 强制渲染页面
						this.$forceUpdate()
						return
					}
					let oldList = this.listCatchData[current] || []
					oldList.push(...data)
					this.$set(this.listCatchData, current, oldList)
				})
			}

<template>
	<swiper @change="change" :current="activeIndex" style="height: 100%">
		<swiper-item style="height: 100%" v-for="(item ,index) in tab" :key="index" class="swiper-item">
			<list-item :list="listCatchData[index]" :load="load[index]" @loadmore="loadmore"></list-item>
		</swiper-item>
	</swiper>
</template>
 
<script>
	export default {
		name: "list",
		props: {
			tab: {
				type: Array,
				default () {
					return []
				}
			},
			activeIndex: {
				type: Number,
				default: 0
			}
		},
		data() {
			return {
				list: [],
				// js 的限制 listCatchData[index] = data
				listCatchData: {},
				load: {},
				pageSize: 10
			};
		},
		watch: {
			tab(newVal) {
				//如果是新的tab
				if (newVal.length === 0) return
				this.listCatchData = {}
				this.load = {}  
				this.getList(this.activeIndex)
			}
		},
		methods: {
			loadmore() {
				//if ‘没有更多数据'就返回 不申请啦
				if (this.load[this.activeIndex].loading === 'noMore') return
				this.load[this.activeIndex].page++
				this.getList(this.activeIndex)
			},
			change(e) {
				const {
					current
				} = e.detail; //取到 current这个数据
				this.$emit('change', current)
				// TODO 当数据不存在 或者 长度是 0 的情况下，才去请求数据 不用每次都加载已经加载过的
				if (!this.listCatchData[current] || this.listCatchData[current].length === 0) {
					this.getList(current)
				}
 
			},
			getList(current) {
				if (!this.load[current]) {//分离page 不能让他们共享一个
					this.load[current] = {
						page: 1,
						loading: 'loading'
					}
				} 
				
				console.log('当前的页数', this.load[current].page);
				this.$api.get_list({ //传三个参数
					name: this.tab[current].name,
					page: this.load[current].page,
					pageSize: this.pageSize
				}).then(res => {
					console.log(res);
					const {
						data
					} = res
					if (data.length === 0) //if没有数据就搞它
						let oldLoad = {}
						oldLoad.loading = 'noMore'
						oldLoad.page = this.load[current].page
						this.$set(this.load, current, oldLoad)
						// 强制渲染页面
						this.$forceUpdate()
						return
					}
					let oldList = this.listCatchData[current] || []//解决每次加载覆盖 没有新的
					oldList.push(...data)
					this.$set(this.listCatchData, current, oldList)
				})
			}
		}
	}
</script>
 
<style lang="sCSS">
	.home-swiper {
		height: 100%;
 
		.swiper-item {
			height: 100%;
			overflow: hidden;
 
			.list-scroll {
				height: 100%;
			}
		}
	}
</style>

<uni-load-more  iconType="snow" :status="load.loading"></uni-load-more>