vue实现直播弹幕功能

1.barrage.less

html,body{
    width:100%;
}
.cute-barrage{
    width: 100%;
    height: 100px;  /*确定弹幕长度*/
    position: absolute;
    top: 1.5rem;   /*确定弹幕高度*/
    left: 0;
    overflow-y: hidden;  /*横向超出部分隐藏*/
    .barrage-div{
        position: absolute;
        left: 0;
        bottom: 0;  /*保证一开始在界面外侧，从右向左就是right，从左向右就是left*/
        height: 0.6rem;
        background-color: rgba(255, 255, 255, 0.9);
        border-radius: 2rem;
        white-space: nowrap;   /*确保内容在一行显示，不然移动到最后会折行*/
        img{
            width: 0.5rem;
            height: 0.5rem;
            vertical-align: middle;  //内联块元素，居中对齐
            padding-left: 0.05rem;
            border-radius: 50%;
        }
        span{
            font-size: 14px;
            padding: 0 0.1rem;
            line-height: 0.6rem;    //内联块元素，居中对齐四个缺一不可
            height: 0.6rem;      //内联块元素，居中对齐四个缺一不可
            display: inline-block;       //内联块元素，居中对齐四个缺一不可
            vertical-align: middle;      //内联块元素，居中对齐四个缺一不可
            i{
                color: #fe5453;
                font-weight: 700;
            }
        }
    }
}

2.barrage.vue

<style lang="less" src="./barrage.less"></style>
<template>
  <div class="barrage">
    <div class="cute-barrage">
      <div class="barrage-div">
        <img
          src="http://kw1-1253445850.file.myqcloud.com/static/image/stimg_7656dc02eb1cd13adbacbdd2695dc3a8.jpg"
        />
        <span>
          么么嗒今天提现
          <i>1Q币</i>
        </span>
      </div>
      <div class="barrage-div">
        <img
          src="http://kw1-1253445850.file.myqcloud.com/static/image/stimg_632fecdcb52417cb8ab89fa283e07281.jpg"
        />
        <span>
          橘色的大耳朵猫今天提现
          <i>5Q币</i>
        </span>
      </div>
      <div class="barrage-div">
        <img
          src="http://kw1-1253445850.file.myqcloud.com/static/image/stimg_632fecdcb52417cb8ab89fa283e07281.jpg"
        />
        <span>
          丶鹿锅里面装着吴奶包今天提现
          <i>3Q币</i>
        </span>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: "barrage",
  components: {},
  props: {},
  data() {
    return {};
  },
  watch: {},
  computed: {},
  methods: {},
  created() {},
  mounted() {
    for (
      let i = 0;
      i < document.getElementsByClassName("barrage-div").length;
      i++
    ) {
      var height = document.getElementsByClassName("barrage-div")[i].clientHeight;
      document.getElementsByClassName("barrage-div")[i].style.bottom = -height;
    //   document.getElementsByClassName("barrage-div")[i].style.top = topRandom; //将弹幕移动到屏幕外面，正好超出的位置
      //拼写动画帧函数，记得每个ani要进行区分，宽度从自己的负宽度移动一整个屏幕的距离
      var keyframes = `\    
        @keyframes ani${i}{   
            form{
                bottom:${-height}px;
            }
            to{
                bottom:100px;
            }
        }\    
        @-webkit-keyframes ani${i}{
            form{
                bottom:${-height}px;
            }
            to{
                bottom:100px;
            }
        }`;
      // 创建style标签
      const style = document.createElement("style");
      // 设置style属性
      style.type = "text/css";
      // 将 keyframes样式写入style内
      style.innerHTML = keyframes;
      // 将style样式存放到head标签
      document.getElementsByTagName("head")[0].appendChild(style);
      //定义动画速度列表
      var aniList = [4, 4, 4, 4, 4];
      //取数组的随机数，0,1,2,3,4
      var aniTime = Math.floor(Math.random() * 5);
      //给当全前弹幕添加animation的css
      //延迟的时间用每个的*1.5倍，这个可变
      document.getElementsByClassName("barrage-div")[i].style.animation=`ani${i} ${aniList[aniTime]}s linear ${i * 1.5}s`
      document.getElementsByClassName("barrage-div")[i].style.webkitAnimation=`ani${i} ${aniList[aniTime]}s linear ${i * 1.5}s`
    }
  }
};
</script>