<el-upload

              class="upload-demo"

              ref="vidos"

              :action="URL+'/api/post/file'"

              :data="date"

              :on-success="handleAvatarAUDIO"

              :before-upload="beforeAvatarAUDIO" //将用到此方法

              :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就是当前视频长度
   })

}