el-upload上传视频来抓取上传视频的时长

通过before-upload限制文件方法来获取视频的时长

 <el-upload
      class="upload-demo"
      action="#"
      :http-request="handleFileUpload"
      :before-upload="handleBeforeUpload">
    <el-button size="small" type="primary">点击上传</el-button>
    <div slot="tip" class="el-upload__tip">
        只能上传90s以内的视频
    </div>
 </el-upload>

handleBeforeUpload(file){
  console.log(file);
  const checkDuration = (file) => {
    return new Promise((resolve, reject) => {
      const videoUrl = URL.createObjectURL(file);
      const video = document.createElement('video');
      video.preload = 'metadata';

      video.onloadedmetadata = () => {
        const duration = video.duration;
        URL.revokeObjectURL(videoUrl); // 释放URL对象
        resolve(duration);
      };

      video.onerror = () => {
        URL.revokeObjectURL(videoUrl); // 释放URL对象
        reject(new Error('视频加载出错'));
      };

      video.src = videoUrl; // 设置视频源
    });
  };

  return checkDuration(file).then(duration => {
    if (duration > 90) {
      this.$message.error('视频时长不能超过90秒！');
      return false;
    }
    console.log(duration);
    return true; // 时长检查通过，可以继续上传
  }).catch(error => {
    this.$message.error('获取视频时长失败：' + error.message);
    return false; // 获取时长失败，阻止上传
  });
},
handleFileUpload(){

}