<input id="file_select" type="file"
 accept=".csv, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, application/vnd.ms-excel" />

<input type="file" accept=".csv" />

<input type="file" accept="application/vnd.ms-excel" />

<input type="file" accept="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" />

<input type="file" accept="text/plain" />

<input type="file" accept="image/*" />

<input type="file" accept="text/html" />

<input type="file" accept="audio/*" />

<input type="file" accept=".pdf" />

/**
   * @desc 下载excel or pdf表格数据, http为使用HttpClient封装的请求Service
   * @param path - 请求path
   * @param params - 参数
   * @param action - 下载的是pdf还是excel
   */
  downloadFile(path: string, params?: any, action = 'pdf'): Observable<any> {
    const token = LocalStorage.get('token')
    const contentType = action === 'pdf' ? 'application/pdf' : 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
    let headers = new HttpHeaders().set('Accept', contentType)
    if (token) {
      headers = headers.set('Authorization', token)
    }
    const options: any = {headers: headers, responseType: 'arraybuffer', observe: 'response'}
    return this.http.get(path, params, options)
      .do((resp: any) => {
        if (resp) {
          this.createATag(resp, action)
        }
      }, e => {
        console.log('e', e)
      })
  }
 
/**
   * @desc 创建a标签，下载excel or pdf
   * @param resp - request response
   * @param action - 下载的使pdf还是excel
   */
  private createATag(resp, action) {
    let fileName = 'Excel文件.xlsx',
      type = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
    if (action === 'pdf') {
      fileName = 'PDF文件.pdf'
      type = 'application/pdf'
    }
    const text = resp.body
    const blob = new Blob([text], {type})
    const downloadLink = document.createElement('a')
    downloadLink.download = `${fileName}`
    downloadLink.href = window.URL.createObjectURL(blob)
    downloadLink.style.display = 'none'
    document.body.appendChild(downloadLink)
    downloadLink.click()
    document.body.removeChild(downloadLink)
  }
  // 调用
  this.downloadFile('export', {action:'download'}, 'pdf').subscribe()