Vue中下拉刷新和上拉加载更多

<template lang="html">
  <div
    class="refresh-moudle"
    @touchstart="touchStart($event)"
    @touchmove="touchMove($event)"
    @touchend="touchEnd($event)"
    ref="myrefresh"
    :style="{ transform: 'translate3d(0,' + top + 'px, 0)' }"
  >
    <header class="pull-refresh">
      <slot name="pull-refresh">
        <div class="down-tip" v-if="dropDownState === 1 || dropDownState === 2">
          <i
            ref="icon"
            class="css-icon icon-upward"
            :class="{ active: dropDownState === 2 }"
          ></i>
          <span class="down-text" v-if="dropDownState === 1">{{
            dropDownInfo.downText
          }}</span>
          <span class="down-text" v-if="dropDownState === 2">{{
            dropDownInfo.upText
          }}</span>
        </div>
        <div class="refresh-tip" v-if="dropDownState === 3">
          <span class="refresh-text">{{ dropDownInfo.refreshText }}</span>
        </div>
      </slot>
    </header>
    <slot></slot>
  </div>
</template>
<script>
export default {
  props: {
    onRefresh: {
      type: Function,
      required: false,
    },
  },
  data() {
    return {
      defaultOffset: 40, // 默认高度, 相应的修改.releshMoudle的margin-top和.down-tip, .up-tip, .refresh-tip的height
      top: 0,
      scrollIsToTop: 0,
      startY: 0,
      isDropDown: false, // 是否下拉
      isRefreshing: false, // 是否正在刷新
      isDropInTop: false, //开始下拉时是否在滚动条已在最上面
      dropDownState: 1, // 显示1:下拉可以刷新, 2:松开立即刷新, 3:正在刷新数据中...
      dropDownInfo: {
        downText: "下拉可以刷新",
        upText: "松开立即刷新",
        refreshText: "正在刷新数据...",
        refreshImg: "loading.png",
      },
    };
  },
  created() {
    if (document.querySelector(".down-tip")) {
      // 获取不同手机的物理像素（dpr）,以便适配rem
      this.defaultOffset =
        document.querySelector(".down-tip").clientHeight || this.defaultOffset;
    }
  },
  methods: {
    /**
     * 触摸开始，手指点击屏幕时
     * @param {object} e Touch 对象包含的属性
     */
    touchStart(e) {
      let dom = this.$refs["myrefresh"];
      this.scrollIsToTop =
        dom.scrollTop || window.pageYOffset || document.body.scrollTop; // safari 获取scrollTop用window.pageYOffset
      if (this.scrollIsToTop === 0) {
        this.startY = e.targetTouches[0].pageY;
        this.isDropInTop = true;
      } else {
        this.isDropInTop = false;
      }
    },

    /**
     * 接触点改变，滑动时
     * @param {object} e Touch 对象包含的属性
     */
    touchMove(e) {
      if (this.isDropInTop) {
        if (e.targetTouches[0].pageY > this.startY) {
          // 下拉
          this.isDropDown = true;
          if (!this.isRefreshing) {
            // 拉动的距离
            let diff =
              e.targetTouches[0].pageY - this.startY - this.scrollIsToTop;
            this.top =
              Math.pow(diff, 0.8) +
              (this.dropDownState === 3 ? this.defaultOffset : 0);
            if (this.top >= this.defaultOffset) {
              this.dropDownState = 2;
              e.preventDefault();
            } else {
              this.dropDownState = 1;
              // 去掉会导致ios无法刷新
              e.preventDefault();
            }
          }
        } else {
          this.isDropDown = false;
          this.dropDownState = 1;
        }
      }
    },

    /**
     * 触摸结束，手指离开屏幕时
     */
    touchEnd() {
      if (this.isDropInTop) {
        if (this.isDropDown && !this.isRefreshing) {
          if (this.top >= this.defaultOffset) {
            this.refresh();
            this.isRefreshing = true;
          } else {
            // cancel refresh
            this.isRefreshing = false;
            this.isDropDown = false;
            this.dropDownState = 1;
            this.top = 0;
          }
        }
      }
    },

    /**
     * 刷新
     */
    refresh() {
      this.dropDownState = 3;
      this.top = this.defaultOffset;
      setTimeout(() => {
        this.onRefresh(this.refreshDone);
      }, 300);
    },

    /**
     * 刷新完成
     */
    refreshDone() {
      this.isRefreshing = false;
      this.isDropDown = false;
      this.dropDownState = 1;
      this.top = 0;
    },
  },
};
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.refresh-moudle {
  width: 100%;
  height: calc(100% + 40px);
  margin-top: -40px;
  -webkit-overflow-scrolling: touch; /* ios5+ */
  overflow-y: scroll;
}

.pull-refresh {
  width: 100%;
  color: #999;
  height: 40px;
  transition-duration: 200ms;
  font-size: 18px;
}

.refresh-moudle .down-tip,
.up-tip,
.refresh-tip {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 40px;
}

.css-icon {
  display: inline-block;
  height: 1em;
  width: 1em;
  font-size: 20px;
  margin-right: 10px;
  box-sizing: border-box;
  text-indent: -9999px;
  vertical-align: middle;
  position: relative;
}

.css-icon::before,
.css-icon::after {
  content: "";
  box-sizing: inherit;
  position: absolute;
  left: 50%;
  top: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.icon-upward::before {
  height: 0.65em;
  width: 0.65em;
  border-style: solid;
  border-width: 2px 0 0 2px;
  -ms-transform: translate(-50%, -50%) rotate(45deg);
  transform: translate(-50%, -50%) rotate(45deg);
}

.icon-upward::after {
  height: 0.8em;
  border-left: 2px solid;
  top: 55%;
}

.icon-upward.active {
  transform: rotate(180deg);
  transition: transform 0.3s;
}

@keyframes anticlockwise {
  0% {
    transform: rotate(-180deg);
  }
  100% {
    transform: rotate(0deg);
  }
}

@keyframes clockwise {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(-180deg);
  }
}

.refresh-img {
  width: 35px;
  height: 35px;
  margin-right: 15px;
  animation: rotating 1.5s linear infinite;
}

@keyframes rotating {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(1turn);
  }
}
</style>

<template>
  <div class="home">
    <div class="msg_list">
      <z-refresh :onRefresh="onRefresh">
          <div class="msg_item" @click="notice_click">
            <div class="msg_top">11111</div>
            <div class="msg_info">
              123456
            </div>
            <div class="msg_time">2021-08-28</div>
          </div>
          
          <div class="loadmore" @click="onLoadMore">点击加载更多</div>
      </z-refresh>
    </div>
  </div>
</template>

<script>
import ZDropDownRefresh from "../components/ZDropDownRefresh";

export default {
  components: {
    "z-refresh": ZDropDownRefresh,
  },
  methods: {
    /**
     * 下拉刷新
     */
    onRefresh(done) {
      // 如果下拉刷新和上拉加载同时使用，下拉时初始化上拉的数据
      console.info("下拉刷新");
      done();
    },
    onLoadMore() {
      console.info("加载更多");
    },
  },
};
</script>