等待用户在 Javascript 中完成下载 blob

Is there any way to achieve this without requiring the user to manually click another button or some such thing to signal the page that he is done saving the file?

推荐答案

这对我有用.

/**
 *
 * @param {object} object A File, Blob, or MediaSource object to create an object URL for. https://developer.mozilla.org/en-US/docs/Web/API/URL/createObjectURL
 * @param {string} filenameWithExtension
 */
function saveObjectToFile (object, filenameWithExtension) {
  console.log('saveObjectToFile: object', object, 'filenameWithExtension', filenameWithExtension)
  const url = window.URL.createObjectURL(object)
  console.log('url', url)
  const link = document.createElement('a')
  link.style.display = 'none'
  link.href = url
  link.target = '_blank'
  link.download = filenameWithExtension
  console.log('link', link)
  document.body.appendChild(link)
  link.click()
  window.setTimeout(function () {
    document.body.removeChild(link)
    window.URL.revokeObjectURL(url)
  }, 0)
}

/**
 * @param {string} path
 * @param {object} payload
 * @param {string} filenameWithExtension
 * @returns {promise}
 */
export async function downloadFileInBackground (path, payload, filenameWithExtension) {
  console.log('downloadFileInBackground awaiting fetch...')
  const response = await fetch(path, {
    method: 'POST',
    cache: 'no-cache',
    headers: {
      'Content-Type': 'application/json'
    },
    body: payload // body data type must match "Content-Type" header
  })
  console.log('response', response)
  const blob = await response.blob()
  saveObjectToFile(blob, filenameWithExtension)
  console.log('downloadFileInBackground finished saving blob to file!', filenameWithExtension)
}

我知道其他人也有这个问题: