element-ui Upload 上傳獲取當前選擇的視頻時長

          <el-upload
              class="upload-demo"
              ref="vidos"
              :action="URL+'/api/post/file'"
              :data="date"
              :on-success="handleAvatarAUDIO"
              :before-upload="beforeAvatarAUDIO" //將用到此方法
              :on-progress="beforeAvatarUpload"
              accept=".mp4"
              :auto-upload="vidoauto"
              :on-change="AvatarAUDIO"
              :file-list="fileList"
            >

beforeAvatarAUDIO(file){
　　let url = URL.createObjectURL(file)
    var audioElement = new Audio(url)
    audioElement.addEventListener('loadedmetadata',function(){
　　　　let playTime = audioElement.duration; //playTime就是當前視頻長度
 })

}