js 显示视频封面

 <video :class="`showupimg video_${sitem.psqid}`">
           <source
            :src="$api.showImageUrl + sitem.useranswer[0]"
            />
</video>

//初始化执行
 getVideoinfo(v) {
      let that = this;
      this.$forceUpdate();
      this.$nextTick(() => {
        let ref = `.video_${v.psqid}`;
        let video = document.querySelector(ref);
        if (video) {
          video.addEventListener("loadedmetadata", function () {
            //v.duration = that.gettime(video.duration); //获取时长
            video.currentTime = 2; // 第2帧位置
          });
        }
      });
    },