组件代码
<template>
<div
class="weui-pull-refresh"
ref="scrollBox"
:style="style"
@touchstart="touchStart"
@touchmove="touchMove"
@touchend="touchEnd">
<div class="weui-pull-present-box" ref="box">
<slot/>
</div>
<div class="weui-pull-refreshing-box">
<div v-if="moveState < 2">{{ moveState === 0 ? '上拉即可加载...' : '释放即可加载...' }}</div>
<div v-else><van-loading color="#0094ff" /> 加载中...</div>
</div>
</div>
</template>
<script>
//如果你想直接拿来用,把create干掉
//import { create } from '../../utils'
//create()干掉
export default ({
name: 'pull-refresh',
data () {
return {
startY: '', //保存touch时的Y坐标
moveDistance: 0, //保存向下滑动的距离
moveState: 0, //开始滑动到结束后状态的变化 0:下拉即可刷新 1:释放即可刷新 2:加载中
duration: 0 //动画持续时间,0就是没有动画
}
},
computed: {
style () {
return {
transition: `${this.duration}ms`,
transform: `translate3d(0,${-this.moveDistance}px, 0)`
}
}
},
methods: {
touchStart (e) {
this.duration = 0 // 关闭动画
this.moveDistance = 0 // 滑动距离归0
this.startY = e.targetTouches[0].clientY // 获得开始Y坐标
},
touchMove (e) { //这里是整个下拉刷新的核心
let scrollTop = document.documentElement.scrollTop || document.body.scrollTop
let clientHeight = document.documentElement.clientHeight || document.body.clientHeight;
let offsetHeight = this.$refs.box.offsetHeight
//首先判断我们的高度是否超过dom高度,如果没有,我们上拉加载就不能启用。
//console.log(scrollTop,clientHeight,offsetHeight);
if (scrollTop+clientHeight < offsetHeight) return
let move = e.targetTouches[0].clientY - this.startY
//判断手指滑动的距离,只有为正数才代表用户下拉了。
if (move < 0) {
//阻止默认事件,在微信浏览器中尤为有用,至于为什么,你去试就知道了。
//e.preventDefault()
//增加滑动阻力的感觉
this.moveDistance = Math.pow(-move, 0.8)
//console.log(this.moveDistance);
if (this.moveDistance > 50) {
//如果滑动距离大于50 那我就告诉你,释放即可刷新
if (this.moveState === 1) return
this.moveState = 1
} else {
//否则 恢复原样
if (this.moveState === 0) return
this.moveState = 0
}
}
},
touchEnd (e) {
// 只要手指拿开,我都需要加上结束时的动画,这里为300ms
this.duration = 300
if (this.moveDistance > 50) {
//这里逻辑跟touchMove一样,但是需要真的加载数据了,那moveState变为2 所以加载动画在这出现
this.moveState = 2
//因为还没加载完,我得让加载动画显示着,所以这里移动距离为50
this.moveDistance = 50
this.$emit('refresh', () => {
//这里就是成功后的回调了,如果该函数被调用,那就以为着加载数据完成,所以状态要回到0,当然需要在父组件调用。
this.moveState = 0
})
} else {
//否则 给我老老实实恢复原样
this.moveDistance = 0
}
}
},
watch: {
//这里是给用户操作返回的核心
moveState (state) {
//我们监听moveState的状态,
//0意味着开始也意味着结束,这里是结束,并且只有动画生效我们才能 moveDistance 设为0,
//为什么动画生效才行,因为动画生效意味着手指离开了屏幕,如果不懂去看touchEnd方法,这时
//我们让距离变为0才会有动画效果。
if (this.duration === 300) {
this.moveDistance = 0
}
}
}
})
</script>
<style scoped lang="scss">
.weui-pull-refresh {
display: flex;
height: calc(100vh - 50px);
flex-direction: column;
.weui-pull-refreshing-box {
line-height: 50px;
height: 50px;
font-size: 14px;
color: rgba(69,90,100,.6);
text-align: center;
margin-bottom:20px;
}
.weui-pull-present-box {
background-color: lighten(#fff, 10%);
}
}
</style>
页面使用代码
//template部分
<pull-refresh @refresh="refresh" v-if="searchBarcodeList.length > 0">
<van-collapse v-model="activeNames" ref="collapse">
<van-collapse-item v-for="(item,index) in searchBarcodeList" :key="index" :value="itemValue(item)" :name="index">
<template #title style="position:relative">
<div class="sort">{{index + 1 }}</div>
<img :src="item.pic || require('../../assets/images/def.png')"
style="object-fit: cover;width: 50px;" @click.stop="lookImg(item.pic)">
<div>{{item.jewelryName}}</div>
</template>
<item-detail :detail="item"/>
</van-collapse-item>
</van-collapse>
</pull-refresh>
//js部分
触底触发
async refresh (done) {
//上拉加载接口请求return promise
await this.scarch()
//请求结束回调
done()
},