移动端下拉刷新，兼容ios，Android及微信浏览器

先看一下效果图

下拉效果的样子参考的新浪微博,滚动加载是ydui的滚动加载组件

因为滚动加载使用的ydui的组件,我这里便不再累述

在线体验点这里

首先分析下拉刷新是怎么实现的

1.页面滚动到顶部时,用户手指向下拖动
2.页面整体开始随着手指向下移动,同时出现下拉的动画
3.用户拖动超过指定长度之后松开手指,页面开始回弹并且执行加载中的动画
4.加载完成之后执行结束的动画

实现原理

一、touchstart事件中
    1.判断是不是滚动到了顶部,如果不是则什么也不用做
    2.判断上次的下拉刷新是不是结束了,如果没有则阻止浏览器默认行为
    3.如果滚动到了顶部 且 没有进行中的下拉刷新 则记录触摸的位置event.touches[0].clientY
二、touchmove事件中
    1.判断是不是滚动到了顶部,如果不是则什么也不用做
    2.判断上次的下拉刷新是不是结束了,如果没有则阻止浏览器默认行为
    3.如果滚动到了顶部 且 没有进行中的下拉刷新
        1.判断手指是向上滑还是向下滑，向上则正常滚动页面，向下则执行下拉刷新
        2.如果手指向下拉，则判断滑动的距离是否超过了指定的距离，超过了则改变动画效果（由下拉刷新-> 释放刷新）
三、touchend事件中
    与touchmove中判断同,唯一不同的是滑动的距离是否超过了指定的距离触发回调并且执行刷新中的动画

获取页面滚动的位置(或者是div内部滚动位置)

/**
     * 传入一个dom对象,返回获取滚动的位置
     * @method getScrollTop
     * @param {dom} dom节点
     * @return {Number} 滚动的位置
     */
    function getScrollTop(element) {
        if (element === window) {
            return Math.max(
                window.pageYOffset || 0,
                document.documentElement.scrollTop
            )
        } else {
            return element.scrollTop
        }
    }

事件处理

//touchstart事件
function touchStartHandler(event) {
    //正在执行下拉刷新则返回
    if (this.touches.loading) {
        event.preventDefault()
        return
    }
    //当向下滚动了则直接返回
    //this.getScrollTop(this.scrollview)获取元素滚动的位置,实现方法见源码
    //this.$refs.dragBox.getBoundingClientRect().top为元素距离窗口顶部的距离
    //this.offsetTop为页面初始化时 this.$refs.dragBox.getBoundingClientRect().top的值
    if (
        this.getScrollTop(this.scrollview) > 0 ||
        this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
    ) {
        return
    }
    //数据初始化
    this.touches.loading = false //是否在下拉刷新回调中
    this.touches.startClientY = 0 //触摸初始位置
    this.touches.isDraging = false //是否开始下拉刷新
    this.touches.statusText = '下拉刷新' //下拉刷新动画中的描述文字
    this.moveOffset = 0 //手指滑动的距离

    //记录触摸位置
    this.touches.startClientY = event.touches[0].clientY
}


//touchmove事件
function touchMoveHandler(event) {
    const touches = this.touches
    //记录当前触摸位置,为了和下一个触摸位置作比较,判断是向上还是向下移动
    touches.currentClientY = event.touches[0].clientY
    //当向下滚动了则直接返回
    if (
        this.getScrollTop(this.scrollview) > 0 ||
        this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
    ) {
        this.touches.isDraging = false //没有开始下拉刷新
        this.moveOffset = 0 //手指滑动的距离0
        return
    }

    //正在执行下拉刷新则返回
    if (this.touches.loading) {
        event.preventDefault()
        return
    }
    //当前触摸的位置
    const currentY = event.touches[0].clientY

    //防止手指直接下滑造成页面不能正常的滚动
    if (!touches.isDraging && currentY < touches.startClientY) {
        return
    }

    //手指先先下拉,再向上滑,说明此时手指已经在触摸位置上方了
    if (
        touches.isDraging &&
        (currentY - touches.startClientY < 0 ||
            this.$refs.dragBox.getBoundingClientRect().top <
                this.offsetTop)
    ) {
        // this.isDragToUp = true;
        event.preventDefault()
        return
    }
    //手指向下滑
    if (touches.isDraging && this.getScrollTop(this.scrollview) === 0) {
        event.preventDefault()
    }

    // //开始下拉刷新
    this.touches.isDraging = true

    //手指滑动的距离
    let deltaSlide = currentY - touches.startClientY
    
    //如果超过了指定的距离, 达到了释放更新的条件
    //touches.distance为顶部加载中动画的高度
    //this.double为手指移动距离和页面实际移动距离的倍数
    if (deltaSlide >= touches.distance * this.double) {
        this.touches.statusText = '释放更新'
    } else {
        this.touches.statusText = '下拉刷新'
    }
    //记录滑动的距离
    this.moveOffset = deltaSlide
}



//touchend事件
function touchEndHandler(event) {
    const touches = this.touches
    
    //正在执行下拉刷新则返回
    if (this.touches.loading) {
        event.preventDefault()
        return
    }

    //当向下滚动了则直接返回
    if (
        this.getScrollTop(this.scrollview) > 0 ||
        this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
    ) {
        this.touches.isDraging = false
        this.moveOffset = 0
        return
    }

    const currentY = event.changedTouches[0].clientY
    
    //说明此时手指已经在触摸位置上方了
    if (
        currentY - touches.startClientY < 0 ||
        this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
    ) {
        this.touches.isDraging = false
        event.preventDefault()
        return
    }
    //下拉刷新阻止浏览器默认行为
    if (this.getScrollTop(this.scrollview) === 0) {
        event.preventDefault()
    }

    //手指滑动的距离
    let deltaSlide = currentY - touches.startClientY
    //如果超过了指定的距离
    if (deltaSlide >= touches.distance * this.double) {
        //进行更新的回调及动画的改变,这部分见源码,耐心的看源码,还是能很容易看明白的
        some code...
    } else {
        this.touches.isDraging = false
        //距离不够则不刷新
        this.Retract(0, false)
    }
}

上方只展示了主要部分,完整源码见文末

然后我把下拉刷新和上拉加载封装为一个vue组件
使用方法

//引入
import YdInfinitescroll from './components/InfiniteScroll.vue'
//注册
components: { YdInfinitescroll }
//使用
<yd-infinitescroll
    :pullcallback="pullcallback"
    :callback="callback"
    ref="infinitescrollDemo"
>
    <div slot='list'>
        ...这里放你的内容
    </div>
</yd-infinitescroll>

说明:

1.传入callback参数表示开启滚动加载功能
    1.this.$refs.infinitescrollDemo.$emit('ydui.infinitescroll.finishLoad')表示单次数据请求完毕
    2.this.$refs.infinitescrollDemo.$emit('ydui.infinitescroll.loadedDone')表示所有数据请求完毕
    3.this.$refs.infinitescrollDemo.$emit('ydui.infinitescroll.reInit')表示重新初始化

2.传入pullcallback参数表示开启下拉刷新功能
    1.更新成功请调用this.$refs.infinitescrollDemo.$emit('ydui.pullrefresh.finishLoad.success',true) 参数 true 开始提示, false 关闭提示, 默认true
    2.更新成功请调用this.$refs.infinitescrollDemo.$emit('ydui.pullrefresh.finishLoad.fail',true) 参数 true 开始提示, false 关闭提示, 默认true
    3.传入pullTipBgColor参数来修改下拉刷新成功状态的背景色,默认蓝色(#171dca)

组件源码,直接copy源码保存为InfiniteScroll.vue即可开始使用

<template>
    <div>
        <!-- 下拉刷新 -->
        <div
            class="dragBox"
            ref="dragBox"
            :style="
                moveOffset
                    ? { transform: `translateY(${moveOffset / double}px)` }
                    : ''
            "
        >
            <!-- 下拉刷新动画效果 -->
            <div
                class="yd-pullTip"
                :style="{
                    height: `${moveOffset / double}px`,
                    top: `-${moveOffset / double}px`,
                    paddingBottom:
                        moveOffset / double > (touches.distance - 20) / 2
                            ? (touches.distance - 20) / 2 + 'px'
                            : `${moveOffset / double}px`
                }"
            >
                <img
                    v-if="touches.loading"
                    src="data:image/gif;base64,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"
                />
                <img
                    v-else
                    :class="{ rotate: moveOffset >= touches.distance * double }"
                    src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACMAAAA4CAYAAAB3yEEBAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAyJpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADw/eHBhY2tldCBiZWdpbj0i77u/IiBpZD0iVzVNME1wQ2VoaUh6cmVTek5UY3prYzlkIj8+IDx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IkFkb2JlIFhNUCBDb3JlIDUuMy1jMDExIDY2LjE0NTY2MSwgMjAxMi8wMi8wNi0xNDo1NjoyNyAgICAgICAgIj4gPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4gPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIgeG1sbnM6eG1wPSJodHRwOi8vbnMuYWRvYmUuY29tL3hhcC8xLjAvIiB4bWxuczp4bXBNTT0iaHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wL21tLyIgeG1sbnM6c3RSZWY9Imh0dHA6Ly9ucy5hZG9iZS5jb20veGFwLzEuMC9zVHlwZS9SZXNvdXJjZVJlZiMiIHhtcDpDcmVhdG9yVG9vbD0iQWRvYmUgUGhvdG9zaG9wIENTNiAoV2luZG93cykiIHhtcE1NOkluc3RhbmNlSUQ9InhtcC5paWQ6OEFFN0NBNENDQkVEMTFFOTg3ODBCRjE0Q0NBQTdFMDEiIHhtcE1NOkRvY3VtZW50SUQ9InhtcC5kaWQ6OEFFN0NBNERDQkVEMTFFOTg3ODBCRjE0Q0NBQTdFMDEiPiA8eG1wTU06RGVyaXZlZEZyb20gc3RSZWY6aW5zdGFuY2VJRD0ieG1wLmlpZDo4QUU3Q0E0QUNCRUQxMUU5ODc4MEJGMTRDQ0FBN0UwMSIgc3RSZWY6ZG9jdW1lbnRJRD0ieG1wLmRpZDo4QUU3Q0E0QkNCRUQxMUU5ODc4MEJGMTRDQ0FBN0UwMSIvPiA8L3JkZjpEZXNjcmlwdGlvbj4gPC9yZGY6UkRGPiA8L3g6eG1wbWV0YT4gPD94cGFja2V0IGVuZD0iciI/Pk84QwMAAALZSURBVHja7Jm7jtpAFIbtgeXiBhvIG6RaEFRcnmIfIc02W20RVtr0KZIiaTYNTV6CJq/ApYpAW21DQwei4SIhQeZf+aDRrD0e20iJlBkJgeZ2vvnPmcN4bK9WKytluRF+D9JMlE0zeLvd3s1ms956vX7ved5zvV5/VywWf8r9bNu2TqdT5Hx2HGXESQEyHo+/73Y7h9odx1m32+2HpEBMB4CKCsSvd0ej0ROvv5Xn0VEmEkaeJAyECup5+7cgoNQwMghf+RkkbLVQaDKZxAZiUa4RVnwLRfb7vaPqR2Wz2bhxFWK6rvFjwdF1Z1QMJXITKaICUe2WODHEomJkOBw+BcVILpc7yP0zmYyVz+cPSRViKpCwGOF5ZNtqtT69mYwxq9vt3hcKhW0ShZjKNSIIFYDwxNbjCW4RNBb1nU6nFwQEhVRALGT7vroGbhFdAwM+SF8lN9oBRC4T51ABMVH+oIQG6UkRGIAhnWyKfuQyOQUQEOyJIcCIXAZBHe0Qcg3/7kfllyCFwlzGE+MXKER2GMWImFnFrSrESF+GiIJCuwwkjiGFeGx+IDfd8GPAx4hg7esmuqB20WXyGC6AO51OH8Hxqgw/RlzLq/Rj5J5AdOJEVXCsCHIZ5l0ul9fnAC6VSnN51wAk6FySpoTFEOwTzKDRaHzlJ7U5dk61Wn2GpDKIbtDq7jLYgb1yufwC++DICh0W3OCBK3SV9iyr4zIeiwvf1vnsnMWKj8cjVj4Qt7P8x6d7jtU9uvLPrzdJjwzLOyCsPm1RzcOSDrwkEBaNT9b6C0XeDATHrH+oGBgDY2AMjIExMAbGwBgYA2NgDMz/BJPk1iI2DD394cZC9dia5NGYJVmxf5NwFed5+iLvm8IMMcYO5Ar6xuWPf8dzho7jtsQxAxjXdefiqj3P+w3FyHBcV6UJ4EGz2fxcqVRe8AID12K1Wu2HleLWy477KjngButir5L/CDAAX5Ad05wlsggAAAAASUVORK5CYII="
                />
                {{ touches.statusText }}
            </div>
            <!-- 下拉刷新提示效果 -->
            <div class="yd-Tip" v-if="pullupdateStatus">
                {{ pullupdateText }}
                <span
                    :style="
                        pullupdateText === '更新成功'
                            ? `backgroundColor: ${pullTipBgColor};`
                            : 'backgroundColor: #aeaeae;'
                    "
                ></span>
            </div>
            <slot name="list"></slot>
        </div>

        <div ref="tag" style="height: 0;"></div>

        <div class="yd-list-loading" v-if="!isDone">
            <div v-show="isLoading">
                <slot name="loadingTip">
                    <template>
                        <svg
                            xmlns="http://www.w3.org/2000/svg"
                            viewBox="0 0 100 100"
                            preserveAspectRatio="xMidYMid"
                            class="lds-ellipsis"
                        >
                            <circle cx="84" cy="50" r="5.04711" fill="#f3b72e">
                                <animate
                                    attributeName="r"
                                    values="10;0;0;0;0"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                                <animate
                                    attributeName="cx"
                                    values="84;84;84;84;84"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                            </circle>
                            <circle cx="66.8398" cy="50" r="10" fill="#E8574E">
                                <animate
                                    attributeName="r"
                                    values="0;10;10;10;0"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="-0.85s"
                                ></animate>
                                <animate
                                    attributeName="cx"
                                    values="16;16;50;84;84"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="-0.85s"
                                ></animate>
                            </circle>
                            <circle cx="32.8398" cy="50" r="10" fill="#43A976">
                                <animate
                                    attributeName="r"
                                    values="0;10;10;10;0"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="-0.425s"
                                ></animate>
                                <animate
                                    attributeName="cx"
                                    values="16;16;50;84;84"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="-0.425s"
                                ></animate>
                            </circle>
                            <circle cx="16" cy="50" r="4.95289" fill="#304153">
                                <animate
                                    attributeName="r"
                                    values="0;10;10;10;0"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                                <animate
                                    attributeName="cx"
                                    values="16;16;50;84;84"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                            </circle>
                            <circle cx="16" cy="50" r="0" fill="#f3b72e">
                                <animate
                                    attributeName="r"
                                    values="0;0;10;10;10"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                                <animate
                                    attributeName="cx"
                                    values="16;16;16;50;84"
                                    keyTimes="0;0.25;0.5;0.75;1"
                                    keySplines="0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1;0 0.5 0.5 1"
                                    calcMode="spline"
                                    dur="1.7s"
                                    repeatCount="indefinite"
                                    begin="0s"
                                ></animate>
                            </circle>
                        </svg>
                    </template>
                </slot>
            </div>
        </div>

        <div class="yd-list-donetip" v-show="!isLoading && isDone">
            <slot name="doneTip">没有更多数据了</slot>
        </div>
    </div>
</template>

<script type="text/babel">
export default {
    name: 'BaseInfinitescroll',
    data() {
        return {
            isLoading: false,
            isDone: false,
            num: 1,

            touches: {
                loading: false, //是否在下拉刷新回调中
                distance: 60, //滑动距离大于100时可释放刷新
                startClientY: 0,
                currentClientY: Math.pow(2, 32), //当前触摸位置
                isDraging: false, //是否开始下拉刷新
                statusText: '下拉刷新' //此时的状态描述
            },
            moveOffset: 0, //手指下拉的长度滚动的
            double: 3, //手滑动距离与下拉距离的倍数
            // step: 20 //松开手指界面向上滑动的速度
            time: 100,
            pullupdateStatus: false, //是否展示下拉刷新更新后的提示
            pullupdateText: '更新成功' //展示下拉刷新更新后的提示
        }
    },
    props: {
        callback: {
            type: Function
        },
        pullcallback: {
            type: Function
        },
        distance: {
            default: 0,
            validator(val) {
                return /^\d*$/.test(val)
            }
        },
        scrollTop: {
            type: Boolean,
            default: true
        },
        pullTipBgColor: {
            type: String,
            default: '#1989fa'
        }
    },
    methods: {
        init() {
            if (this.scrollTop) {
                if (this.scrollview === window) {
                    window.scrollTo(0, 0)
                } else {
                    this.scrollview.scrollTop = 0
                }
            }
            this.scrollview.addEventListener(
                'scroll',
                this.throttledCheck,
                false
            )
            this.$on('ydui.infinitescroll.loadedDone', () => {
                this.isLoading = false
                this.isDone = true
            })
            this.$on('ydui.infinitescroll.finishLoad', () => {
                this.isLoading = false
            })
            this.$on('ydui.infinitescroll.reInit', () => {
                this.isLoading = false
                this.isDone = false
            })
        },
        pullinit() {
            const dragBox = this.$refs.dragBox
            dragBox.addEventListener('touchstart', this.touchStartHandler)
            dragBox.addEventListener('touchmove', this.touchMoveHandler)
            dragBox.addEventListener('touchend', this.touchEndHandler)
            //防止微信浏览器下拉出现域名
            document.body.addEventListener('touchmove', this.stopDragEvent, {
                passive: false //调用阻止默认行为
            })
            //容器距离顶部的距离
            this.offsetTop = this.$refs.dragBox.getBoundingClientRect().top
            //上拉加载完成
            this.$on('ydui.pullrefresh.finishLoad.success', (tip = true) => {
                this.pullupdateText = '更新成功'
                this.Retract(0, tip)
            })
            this.$on('ydui.pullrefresh.finishLoad.fail', (tip = true) => {
                this.pullupdateText = '更新失败'
                this.Retract(0, tip)
            })
            // eslint-disable-next-line no-unused-vars
            this.$on('ydui.pullrefresh.finishLoad.load', (tip = true) => {
                this.touches.statusText = '加载中'
                this.touches.loading = true
                this.moveOffset = this.double * this.touches.distance
                this.pullupdateStatus = false
            })
        },
        scrollHandler() {
            if (this.isLoading || this.isDone) return
            const scrollview = this.scrollview
            const contentHeight = document.body.offsetHeight
            const isWindow = scrollview === window
            const offsetTop = isWindow
                ? 0
                : scrollview.getBoundingClientRect().top
            const scrollviewHeight = isWindow
                ? contentHeight
                : scrollview.offsetHeight
            if (!scrollview) {
                // eslint-disable-next-line
                console.warn("Can't find the scrollview!")
                return
            }
            if (!this.$refs.tag) {
                // eslint-disable-next-line
                console.warn("Can't find the refs.tag!")
                return
            }
            const tagOffsetTop =
                Math.floor(this.$refs.tag.getBoundingClientRect().top) - 1
            const distance =
                !!this.distance && this.distance > 0
                    ? ~~this.distance
                    : Math.floor(contentHeight / 10)
            if (
                tagOffsetTop > offsetTop &&
                tagOffsetTop - (distance + offsetTop) * this.num <=
                    contentHeight &&
                this.$el.offsetHeight > scrollviewHeight
            ) {
                this.isLoading = true
                this.callback && this.callback()
                this.num++
            }
        },
        throttle(method, context) {
            clearTimeout(method.tId)
            method.tId = setTimeout(() => {
                method.call(context)
            }, 30)
        },
        throttledCheck() {
            this.throttle(this.scrollHandler)
        },
        getScrollview(el) {
            let currentNode = el
            while (
                currentNode &&
                currentNode.tagName !== 'HTML' &&
                currentNode.tagName !== 'BODY' &&
                currentNode.nodeType === 1
            ) {
                let overflowY = document.defaultView.getComputedStyle(
                    currentNode
                ).overflowY
                if (overflowY === 'scroll' || overflowY === 'auto') {
                    return currentNode
                }
                currentNode = currentNode.parentNode
            }
            return window
        },
        /**
         * 获取滚动的位置
         * @method getScrollTop
         * @return {Number} 滚动的位置
         */
        getScrollTop(element) {
            if (element === window) {
                return Math.max(
                    window.pageYOffset || 0,
                    document.documentElement.scrollTop
                )
            } else {
                return element.scrollTop
            }
        },
        touchStartHandler(event) {
            //正在执行下拉刷新则返回
            if (this.touches.loading) {
                event.preventDefault()
                return
            }
            //当向下滚动了则直接返回
            if (
                this.getScrollTop(this.scrollview) > 0 ||
                this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
            ) {
                return
            }
            //数据初始化
            this.touches.loading = false
            this.touches.startClientY = 0
            this.touches.isDraging = false
            this.touches.statusText = '下拉刷新'
            this.moveOffset = 0

            //记录触摸位置
            // this.touches.startClientX = event.touches[0].clientX
            this.touches.startClientY = event.touches[0].clientY
        },
        touchMoveHandler(event) {
            const touches = this.touches
            //记录当前触摸位置
            touches.currentClientY = event.touches[0].clientY
            //当向下滚动了则直接返回
            if (
                this.getScrollTop(this.scrollview) > 0 ||
                this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
            ) {
                // this.dragTip.translate = 0;
                // this.resetParams();
                this.touches.isDraging = false
                this.moveOffset = 0
                return
            }

            //正在执行下拉刷新则返回
            if (this.touches.loading) {
                event.preventDefault()
                return
            }
            // console.log(this.getScrollTop(this.scrollview))

            // console.log('执行了')
            const currentY = event.touches[0].clientY
            // const currentX = event.touches[0].clientX

            //防止手指直接下滑造成页面不能正常的滚动
            if (!touches.isDraging && currentY < touches.startClientY) {
                return
            }

            //手指先先下拉,再向上滑,说明此时手指已经在触摸位置上方了
            if (
                touches.isDraging &&
                (currentY - touches.startClientY < 0 ||
                    this.$refs.dragBox.getBoundingClientRect().top <
                        this.offsetTop)
            ) {
                // this.isDragToUp = true;
                event.preventDefault()
                return
            }
            //手指向下滑
            if (touches.isDraging && this.getScrollTop(this.scrollview) === 0) {
                event.preventDefault()
            }

            // //开始下拉刷新
            this.touches.isDraging = true

            // const touchAngle =
            //     (Math.atan2(
            //         Math.abs(currentY - touches.startClientY),
            //         Math.abs(currentX - touches.startClientX)
            //     ) *
            //         180) /
            //     Math.PI
            // if (90 - touchAngle > 45) return

            //手指滑动的距离
            let deltaSlide = currentY - touches.startClientY
            //如果超过了指定的距离, 达到了释放更新的条件
            if (deltaSlide >= touches.distance * this.double) {
                this.touches.statusText = '释放更新'
            } else {
                this.touches.statusText = '下拉刷新'
            }
            //记录滑动的位置
            this.moveOffset = deltaSlide
            // console.log(this.moveOffset)
        },
        touchEndHandler(event) {
            const touches = this.touches
            // console.log(this.touches.isDraging)
            //正在执行下拉刷新则返回
            if (this.touches.loading) {
                event.preventDefault()
                return
            }

            //当向下滚动了则直接返回
            if (
                this.getScrollTop(this.scrollview) > 0 ||
                this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
            ) {
                this.touches.isDraging = false
                this.moveOffset = 0
                return
            }

            const currentY = event.changedTouches[0].clientY
            // const currentX = event.changedTouches[0].clientX
            //说明此时手指已经在触摸位置上方了
            if (
                currentY - touches.startClientY < 0 ||
                this.$refs.dragBox.getBoundingClientRect().top < this.offsetTop
            ) {
                this.touches.isDraging = false
                event.preventDefault()
                return
            }
            //下拉刷新阻止浏览器默认行为
            if (
                this.getScrollTop(this.scrollview) === 0 &&
                currentY !== this.touches.startClientY
            ) {
                event.preventDefault()
            }

            //手指滑动的距离
            let deltaSlide = currentY - touches.startClientY
            //如果超过了指定的距离
            if (deltaSlide >= touches.distance * this.double) {
                //进行更新的动画
                this.touches.statusText = '加载中'
                // alert('下拉刷新')
                this.touches.startClientY = 0
                this.touches.isDraging = false
                this.Retract(touches.distance * this.double)
                return
            } else {
                this.touches.isDraging = false
                //距离不够则不刷新
                this.Retract(0, false)
            }
        },
        stopDragEvent(event) {
            this.touches.isDraging && event.preventDefault()
        },
        Retract(offsetTop, tip) {
            let timer = setInterval(() => {
                //根据时间计算出每次运动的距离
                // 总时间 / 每次运动时间 = 运动次数
                // 总长度 / 运动次数 = 每次运动距离
                let step = (
                    (this.touches.distance * this.double) /
                    ((this.time * 60) / 1000).toFixed(2)
                ).toFixed(2)
                if (this.moveOffset - step > offsetTop) {
                    this.moveOffset -= step
                } else {
                    this.moveOffset = offsetTop
                    clearInterval(timer)
                    if (offsetTop !== 0) {
                        this.touches.loading = true
                        this.pullcallback && this.pullcallback()
                    } else {
                        //重置
                        this.touches.loading = false
                        this.touches.startClientY = 0
                        this.touches.isDraging = false
                        this.touches.statusText = '下拉刷新'
                        //执行加载中动画
                        if (tip) {
                            //执行更新成功或者失败动画
                            this.pullupdateStatus = true
                            setTimeout(() => {
                                this.pullupdateStatus = false
                            }, 1000)
                        }
                    }
                }
            }, 1000 / 60)
        }
    },
    mounted() {
        // console.log(this.distance, this.touches)
        this.scrollview = this.getScrollview(this.$el)
        if (this.callback) {
            this.init()
        }
        if (this.pullcallback) {
            this.pullinit()
        }
    },
    beforeDestroy() {
        this.scrollview.removeEventListener('scroll', this.throttledCheck)
        this.$refs.dragBox.removeEventListener(
            'touchstart',
            this.touchStartHandler
        )
        this.$refs.dragBox.removeEventListener(
            'touchmove',
            this.touchMoveHandler
        )
        this.$refs.dragBox.removeEventListener('touchend', this.touchEndHandler)
        document.body.removeEventListener('touchmove', this.stopDragEvent)
    }
}
</script>

<style lang="scss" scoped>
@keyframes intact {
    0% {
        border-radius: 50%;
    }
    100% {
        border-radius: 0%;
    }
}
.dragBox {
    position: relative;
}
.yd {
    &-list-loading {
        padding: 0.1rem 0;
        text-align: center;
        font-size: 0.26rem;
        color: #999;
        height: 0.66rem;
        box-sizing: content-box;
        &-box {
            height: 0.66rem;
            overflow: hidden;
            line-height: 0.66rem;
        }
        img {
            height: 0.66rem;
            display: inline-block;
        }
        svg {
            width: 0.66rem;
            height: 0.66rem;
        }
    }

    &-list-donetip {
        font-size: 0.24rem;
        text-align: center;
        padding: 0.25rem 0;
        color: #777;
    }
    &-pullTip {
        text-align: center;
        font-size: 0.24rem;
        position: absolute;
        left: 0;
        right: 0;
        background: #eeeeee;
        color: #a5a5a5;
        overflow: hidden;
        display: flex;
        align-items: flex-end;
        justify-content: center;
        img {
            height: 20px;
            margin-right: 12px;
            margin-bottom: -1px;
            transition: transform 0.1s linear;
            transform: rotate(180deg);
        }
        img.rotate {
            transform: rotate(0deg);
        }
    }
    &-Tip {
        z-index: 99999999;
        position: absolute;
        left: 0;
        right: 0;
        top: 0;
        height: 36px;
        line-height: 36px;
        font-size: 0.26rem;
        overflow: hidden;
        text-align: center;
        color: #fff;
        span {
            position: absolute;
            top: 0;
            left: 0;
            z-index: -1;
            display: block;
            width: 100%;
            padding-top: 100%;
            border-radius: 50%;
            animation: intact 0.1s linear forwards;
        }
    }
}
</style>