在函数中获取blob已下载状态

function downloadBlob(url) {
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', url);
    xhr.responseType = 'blob';

    xhr.onload = () => {
      if (xhr.status === 200) {
        resolve(xhr.response);
      } else {
        reject(new Error(`Download failed with status ${xhr.status}`));
      }
    };

    xhr.onprogress = (event) => {
      const downloadedBytes = event.loaded;
      const totalBytes = event.total;
      const progress = Math.round((downloadedBytes / totalBytes) * 100);
      console.log(`Download progress: ${progress}%`);
    };

    xhr.onerror = () => {
      reject(new Error('Download failed'));
    };

    xhr.send();
  });
}

// 示例用法
const blobUrl = 'https://example.com/image.jpg';
downloadBlob(blobUrl)
  .then((blob) => {
    // 下载完成后的处理逻辑
    console.log('Download completed');
  })
  .catch((error) => {
    // 下载失败的处理逻辑
    console.error(error);
  });