vue组件：列表自动无限循环

前述：用过vue-seamless-scroll插件，手动滚动列表到底部出现了空白现象，某些表现不符合项目场景，故自己写了一个自己用的组件，如果有人需要可以直接拿去用，如有不足请指教勿喷！

主要功能：

1. 列表自动无限循环滚动
2. 鼠标移入停止滚动，移出继续滚动
3. 待滚动内容高度未铺满并超过容器高度时不滚动
4. 支持滚动速度、单次滚动时间间隔、单次滚动高度，三个参数控制
5. 可自己手动滚动列表

效果图 ：

组件代码：

<template>
  <div class="scroll-outer" ref="outer" @mouseover="onMouseover" @mouseleave="onMouseleave">
    <div class="scroll-inner-box" ref="scrollBox">
      <div class="scroll-item-box" ref="scrollItemBox">
        <slot></slot>
      </div>
      <div v-if="showSecond" class="scroll-item-box">
        <slot></slot>
      </div>
    </div>
  </div>
</template>
  <script>
export default {
  name: "my-auto-scroll",
  props: {
    list: {
      type: Array,
      default: () => [
        { name: "张三1" },
        { name: "张三2" },
        { name: "张三3" },
        { name: "张三4" },
        { name: "张三5" },
        { name: "张三6" },
        { name: "张三7" },
        { name: "张三8" },
        { name: "张三9" },
        { name: "张三10" },
      ],
    },
    speed: {
      type: Number,
      default: 0.1,
    },
    //滚动作单步运动时的单纯运动距离
    singleHeight: {
      type: Number,
      default: 0,
    },
    //单步运动的时间间隔
    waitTime: {
      type: Number,
      default: 0,
    },
  },
  data() {
    return {
      rafId: null,
      y: 0,
      showSecond: false,
      controleHeight: 0,
    };
  },
  watch: {
    list: {
      handler(newVal) {
        var that = this;
        this.$nextTick(() => {
          console.log(newVal);
          if (newVal && newVal.length > 0) {
            let scrollBox = that.$refs.scrollBox;
            let outer = that.$refs.outer;

            if (this.myReq) {
              cancelAnimationFrame(this.myReq);
            }
            // 开启动画
            if (this.canRun()) this.reqAnimationFrame();
            // this.reqAnimationFrame();
            // 手动滚动到底部时滚动条重置到最上边,同时滚动盒子重置为top:0
            outer.addEventListener("scroll", function () {
              if (
                outer.scrollTop + outer.clientHeight + 4 >=
                outer.scrollHeight
              ) {
                outer.scrollTop = 0;
                that.y = 0;
                scrollBox.style.top = 0;
              }
            });
          }
        });
      },
      deep: true,
      immediate: true,
    },
  },
  mounted() {
    window.addEventListener("resize", this.listenResizeFn);
  },
  methods: {
    listenResizeFn() {
      cancelAnimationFrame(this.myReq);
      if (this.canRun()) this.reqAnimationFrame();
    },
    onMouseover() {
      clearTimeout(this.timer);
      cancelAnimationFrame(this.myReq);
    },
    onMouseleave() {
      if (this.canRun()) this.reqAnimationFrame();
    },
    canRun() {
      let scrollItemBox = this.$refs.scrollItemBox;
      let scrollBox = this.$refs.scrollBox;
      let outer = this.$refs.outer;
      // 开启动画条件：滚动盒子(scrollBox)高度高于外层容器(outer)高度
      if (outer.offsetHeight >= scrollItemBox.offsetHeight) {
        this.showSecond = false;
        outer.scrollTop = 0;
        this.y = 0;
        scrollBox.style.top = 0;
        return false;
      } else {
        this.showSecond = true;
        return true;
      }
    },
    //获取dom元素的高度：content+padding+margin+border
    getComputedHeight(dom) {
      let computedStyle = getComputedStyle(dom);

      let computedHeight =
        dom.offsetHeight +
        parseFloat(computedStyle.marginTop) +
        parseFloat(computedStyle.marginBottom);
      return computedHeight;
    },
    reqAnimationFrame() {
      //外层容器
      let outer = this.$refs.outer;
      //滚动盒子
      let scrollBox = this.$refs.scrollBox;
      //滚动盒子下边的第一个scroll-item-box，
      let scrollItemBox = this.$refs.scrollItemBox;

      //滚动速度
      this.speed = this.speed > 1 ? 1 : this.speed < 0 ? 0.1 : this.speed;

      //取第一个scrollItemBox高度
      let definedHeight = this.getComputedHeight(scrollItemBox);
      //持续滚动
      this.y = this.y + this.speed;
      scrollBox.style.top = -this.y + "px";

      //====添加滚动间隔控制====开始
      if (this.singleHeight >= 20 && this.waitTime > 500) {
        if (this.controleHeight >= this.singleHeight) {
          cancelAnimationFrame(this.myReq);
          this.controleHeight = 0;
          this.timer = setTimeout(() => {
            if (this.canRun) this.reqAnimationFrame();
          }, this.waitTime);
          return;
        } else {
          // 一次移动高度未达到指定距离继续执行动画
          this.controleHeight += this.speed;
        }
      }
      //====添加滚动间隔控制====结束

      //当滚动到第一个scroll-item-box高度时scrollBox重置为top:0,视觉上是无缝滚动
      if (this.y >= definedHeight) {
        this.y = 0;
      }
      this.myReq = window.requestAnimationFrame(this.reqAnimationFrame);
    },
  },
  destroyed() {
    window.removeEventListener("resize", this.listenResizeFn);
    cancelAnimationFrame(this.myReq);
    if (this.timer) clearTimeout(this.timer);
  },
};
</script>
  <style lang="scss">
.scroll-outer {
  height: 100%;
  overflow-x: hidden;
  position: relative;
  &::-webkit-scrollbar {
    width: 0.3vw;
  }
  &:hover::-webkit-scrollbar-track {
    -webkit-box-shadow: inset 0 0 0.1vw rgba(0, 0, 0, 0.3);
    border-radius: 0.1vw;
    background-color: #295099;
    opacity: 1;
    // display: none;
  }
  &:hover::-webkit-scrollbar-thumb {
    opacity: 1;
    border-radius: 0.1vw;
    -webkit-box-shadow: inset 0 0 0.1vw rgba(0, 0, 0, 0.3);
    background-color: #0ba9ea;
  }
}
.scroll-inner-box {
  height: auto;
  position: absolute;
  width: 100%;
  top: 0;
  left: 0;
}
</style>
  
  

使用示例：

import autoScroll from "@/components/autoScroll";

<autoScroll :list="list" :speed="0.5" :waitTime="2000" :singleHeight="100">
            <div class="t-item" v-for="(item,index) in list" :key="index">
              <div class="tvalue" style="flex: 0 0 30%;">{{ item.jgjc }}</div>
              <span class="tvalue">{{ item.total||'--' }}</span>
              <span class="tvalue" style="color:#0FCBDE">{{ item.ypc||'--' }}</span>
              <span class="tvalue" style="color:#F15730">{{ item.zlz||'--' }}</span>
              <span class="tvalue" style="color:#17DB68">{{ item.zlwc||'--' }}</span>
            </div>
          </autoScroll>

使用注意：

1. autoScroll容器默认是占外层容器宽高百分百，要自己在autoScroll外层加个容器
2. 参数waitTIme和singleHeight同时存在，才能出现滚动动画间隔执行的效果
3. 样式用了sass，如果有问题可以去掉或者导入sass