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分手后的思念是犯贱 2024-03-26 14:52 30阅读 0赞

本文实例为大家分享了vue2实现上拉加载展示的具体代码，供大家参考，具体内容如下

因为我们项目中，还用了swiper。很多都是滑动切换的，但是又得上拉加载，所以导致，很多UI框架，我们用了，都有不同的bug出现，没办法，最后写了一个。代码如下（这个因为很多地方会用，所以建议放在components/common下面）：

<template>
      <div class="loadmore">
        <slot></slot>
        <slot name="bottom">
        </slot>
      </div>
    </template>
    
    <style>
      .loadmore{
        width:100%;
      }
    </style>
    
    <script>
      export default {
        name: 'loadmore',
        props: {
          maxDistance: {
            type: Number,
            default: 0
          },
          autoFill: {
            type: Boolean,
            default: true
          },
          distanceIndex: {
            type: Number,
            default: 2
          },
          bottomPullText: {
            type: String,
            default: '上拉刷新'
          },
          bottomDropText: {
            type: String,
            default: '释放更新'
          },
          bottomLoadingText: {
            type: String,
            default: '加载中...'
          },
          bottomDistance: {
            type: Number,
            default: 70
          },
          bottomMethod: {
            type: Function
          },
          bottomAllLoaded: {
            type: Boolean,
            default: false
          },
        },
        data() {
          return {
            // 最下面出现的div的位移
            translate: 0,
            // 选择滚动事件的监听对象
            scrollEventTarget: null,
            containerFilled: false,
            bottomText: '',
            // class类名
            bottomDropped: false,
            // 获取监听滚动元素的scrollTop
            bottomReached: false,
            // 滑动的方向  down---向下互动；up---向上滑动
            direction: '',
            startY: 0,
            startScrollTop: 0,
            // 实时的clientY位置
            currentY: 0,
            topStatus: '',
            // 上拉加载的状态  ''   pull: 上拉中
            bottomStatus: '',
          };
        },
        watch: {
          // 改变当前加载在状态
          bottomStatus(val) {
            this.$emit('bottom-status-change', val);
            switch (val) {
              case 'pull':
                this.bottomText = this.bottomPullText;
                break;
              case 'drop':
                this.bottomText = this.bottomDropText;
                break;
              case 'loading':
                this.bottomText = this.bottomLoadingText;
                break;
            }
          }
        },
        methods: {
          onBottomLoaded() {
            this.bottomStatus = 'pull';
            this.bottomDropped = false;
            this.$nextTick(() => {
              if (this.scrollEventTarget === window) {
              document.body.scrollTop += 50;
            } else {
              this.scrollEventTarget.scrollTop += 50;
            }
            this.translate = 0;
          });
            // 注释
            if (!this.bottomAllLoaded && !this.containerFilled) {
              this.fillContainer();
            }
          },
    
          getScrollEventTarget(element) {
            let currentNode = element;
            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scrollTop
          getScrollTop(element) {
            if (element === window) {
              return Math.max(window.pageYOffset || 0, document.documentElement.scrollTop);
            } else {
              return element.scrollTop;
            }
          },
          bindTouchEvents() {
            this.$el.addEventListener('touchstart', this.handleTouchStart);
            this.$el.addEventListener('touchmove', this.handleTouchMove);
            this.$el.addEventListener('touchend', this.handleTouchEnd);
          },
          init() {
            this.bottomStatus = 'pull';
            // 选择滚动事件的监听对象
            this.scrollEventTarget = this.getScrollEventTarget(this.$el);
            if (typeof this.bottomMethod === 'function') {
              // autoFill 属性的实现  注释
              this.fillContainer();
              // 绑定滑动事件
              this.bindTouchEvents();
            }
          },
          // autoFill 属性的实现  注释
          fillContainer() {
            if (this.autoFill) {
              this.$nextTick(() => {
                if (this.scrollEventTarget === window) {
                this.containerFilled = this.$el.getBoundingClientRect().bottom >=
                    document.documentElement.getBoundingClientRect().bottom;
              } else {
                this.containerFilled = this.$el.getBoundingClientRect().bottom >=
                    this.scrollEventTarget.getBoundingClientRect().bottom;
              }
              if (!this.containerFilled) {
                this.bottomStatus = 'loading';
                this.bottomMethod();
              }
            });
            }
          },
          // 获取监听滚动元素的scrollTop
          checkBottomReached() {
            if (this.scrollEventTarget === window) {
              return document.body.scrollTop + document.documentElement.clientHeight >= document.body.scrollHeight;
            } else {
              // getBoundingClientRect用于获得页面中某个元素的左，上，右和下分别相对浏览器视窗的位置。 right是指元素右边界距窗口最左边的距离，bottom是指元素下边界距窗口最上面的距离。
              return this.$el.getBoundingClientRect().bottom <= this.scrollEventTarget.getBoundingClientRect().bottom + 1;
            }
          },
          // ontouchstart 事件
          handleTouchStart(event) {
            // 获取起点的y坐标
            this.startY = event.touches[0].clientY;
            this.startScrollTop = this.getScrollTop(this.scrollEventTarget);
            this.bottomReached = false;
            if (this.bottomStatus !== 'loading') {
              this.bottomStatus = 'pull';
              this.bottomDropped = false;
            }
          },
          // ontouchmove事件
          handleTouchMove(event) {
            if (this.startY < this.$el.getBoundingClientRect().top && this.startY > this.$el.getBoundingClientRect().bottom) {
              // 没有在需要滚动的范围内滚动，不再监听scroll
              return;
            }
            // 实时的clientY位置
            this.currentY = event.touches[0].clientY;
            // distance 移动位置和开始位置的差值    distanceIndex---
            let distance = (this.currentY - this.startY) / this.distanceIndex;
            // 根据 distance 判断滑动的方向 并赋予变量  direction down---向下互动；up---向上滑动
            this.direction = distance > 0 ? 'down' : 'up';
            if (this.direction === 'up') {
              // 获取监听滚动元素的scrollTop
              this.bottomReached = this.bottomReached || this.checkBottomReached();
            }
            if (typeof this.bottomMethod === 'function' && this.direction === 'up' &&
                this.bottomReached && this.bottomStatus !== 'loading' && !this.bottomAllLoaded) {
              // 有加载函数，是向上拉，有滚动距离，不是正在加载ajax，没有加载到最后一页
              event.preventDefault();
              event.stopPropagation();
              if (this.maxDistance > 0) {
                this.translate = Math.abs(distance) <= this.maxDistance
                    ? this.getScrollTop(this.scrollEventTarget) - this.startScrollTop + distance : this.translate;
              } else {
                this.translate = this.getScrollTop(this.scrollEventTarget) - this.startScrollTop + distance;
              }
              if (this.translate > 0) {
                this.translate = 0;
              }
              this.bottomStatus = -this.translate >= this.bottomDistance ? 'drop' : 'pull';
            }
          },
          // ontouchend事件
          handleTouchEnd() {
            if (this.direction === 'up' && this.bottomReached && this.translate < 0) {
              this.bottomDropped = true;
              this.bottomReached = false;
              if (this.bottomStatus === 'drop') {
                this.translate = '-50';
                this.bottomStatus = 'loading';
                this.bottomMethod();
              } else {
                this.translate = '0';
                this.bottomStatus = 'pull';
              }
            }
            this.direction = '';
          }
        },
        mounted() {
          this.init();
        }
      };
    </script>

然后哪个页面需要，在哪个页面导入即可：import LoadMore from './../common/loadmore.vue';在需要引入他的页面写法如下：

<template>
     <section class="finan">
      
      <load-more
      :bottom-method="loadBottom"
      :bottom-all-loaded="allLoaded"
      :bottomPullText='bottomText'
      :auto-fill="false"
      @bottom-status-change="handleBottomChange"
      ref="loadmore">
        <div>
      这里写你需要的另外的模块
        </div>
        <div v-show="loading" slot="bottom" class="loading"> 这个div是为让上拉加载的时候显示一张加载的gif图
         <img src="./../../assets/main/uploading.gif">
        </div>
      </load-more>
     </section>
    </template>

然后在此页面的data里和methods设置如下：

JavaScript

exportdefault{
        name:'FinancialGroup',
        props:{},
        data (){return{// 上拉加载数据
            scrollHeight:0,
            scrollTop:0,
            containerHeight:0,
            loading:false,
            allLoaded:false,
            bottomText:'上拉加载更多...',
            bottomStatus:'',
            pageNo:1,
            totalCount:'',}},
        methods:{/* 下拉加载 */
        _scroll:function(ev){
          ev = ev || event;this.scrollHeight =this.$refs.innerScroll.scrollHeight;this.scrollTop =this.$refs.innerScroll.scrollTop;this.containerHeight =this.$refs.innerScroll.offsetHeight;},
        loadBottom:function(){this.loading =true;this.pageNo +=1;// 每次更迭加载的页数if(this.pageNo ==this.totalGetCount){// 当allLoaded = true时上拉加载停止this.loading =false;this.allLoaded =true;}
          api.commonApi(后台接口，请求参数) 这个api是封装的axios有不懂的可以看vue2+vuex+axios那篇文章
              .then(res =>{setTimeout(()=>{
          要使用的后台返回的数据写在setTimeout里面
             this.$nextTick(()=>{this.loading =false;})},1000)});},handleBottomChange(status){this.bottomStatus = status;},}

这样就完成了。