js 文件下载功能

import { message } from 'antd'

export function getBlob(url: string): Promise<any> {

  return new Promise(resolve => {

    const xhr = new XMLHttpRequest()

    xhr.open('GET', url, true)

    xhr.setRequestHeader('Authorization', window.localStorage.getItem('token'))

    xhr.responseType = 'blob'

    message.loading('', 0)

    xhr.onload = () => {

      message.destroy()

      if (xhr.status === 200) {

        if (xhr.response.type == 'application/json') {

          var reader = new FileReader()

          reader.addEventListener('loadend', function (e) {

            let res = JSON.parse(e.target.result as any)

            if (res?.code != 200) {

              message.error(res.message)

            }

          })

          reader.readAsText(xhr.response)

          return

        }

        resolve({

          blob: xhr.response,

          fileName: getFileName(xhr),

        })

      }

    }

    xhr.send()

  })

}

function getFileName(xhr) {

  var filename = ''

  var disposition = xhr.getResponseHeader('Content-Disposition')

  if (disposition && disposition.indexOf('attachment') !== -1) {

    var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/

    var matches = filenameRegex.exec(disposition)

    if (matches != null && matches[1]) {

      filename = matches[1].replace(/['"]/g, '')

    }

  }

  return filename

}

export function saveBlob(

  blob: Blob,

  blobFileName?: string,

  filename?: string

): void {

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment

  // @ts-ignore

  if (window.navigator.msSaveOrOpenBlob) {

    ;(window.navigator as any).msSaveBlob(blob, filename)

  } else {

    const link = document.createElement('a')

    const body: HTMLBodyElement = document.querySelector(

      'body'

    ) as HTMLBodyElement

    link.href = window.URL.createObjectURL(blob)

    if (filename) {

      if (blobFileName) {

        link.download = filename + '.' + blobFileName.split('.').pop()

      }

    } else {

      link.download = blobFileName ? decodeURI(blobFileName) : null

    }

    link.style.display = 'none'

    body.appendChild(link)

    link.click()

    body.removeChild(link)

    window.URL.revokeObjectURL(link.href)

  }

}

export const downloadFile = async (url: string, filename?: string) => {

  if (!url) return

  const blobFile = await getBlob(url)

  saveBlob(blobFile.blob, blobFile.fileName, filename)

}