input file accept，上传文件、下载文件类型限制格式 ，常用MIME类型列表

上传文件input格式

上传文件浏览时只显示指定文件类型 xls、xlsx、csv（多种类型组合）

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

合法的指定类型：
CSV files (.csv):

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

Excel Files 2003-2007 (.xls):

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

Excel Files 2010 (.xlsx):

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

Text Files (.txt):

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

Image Files (.png/.jpg/etc):

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

HTML Files (.htm,.html):

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

Audio Files (.mp3, .wav, etc):

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

PDF Files:

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

下载文件示例

/**
   * @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()

常用MIME

文件拓展名	MIME类型
.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.xltx	application/vnd.openxmlformats-officedocument.spreadsheetml.template
.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation
*.css	text/css
*.csv	text/csv
.doc，.dot	application/msword
*.gif	image/gif
.htm，.html	text/html
*.jpeg	image/jpeg
*.jpg	image/jpeg
*.js	text/javascript, application/javascript
*.json	application/json
*.pdf	application/pdf
*.png	image/png
*.txt	text/plain
*.zip	aplication/zip

不常用MIME

文件拓展名	MIME类型
.docm	application/vnd.ms-word.document.macroEnabled.12
.dotx	application/vnd.openxmlformats-officedocument.wordprocessingml.template
.dotm	application/vnd.ms-word.template.macroEnabled.12
.xlsm	application/vnd.ms-excel.sheet.macroEnabled.12
.xltm	application/vnd.ms-excel.template.macroEnabled.12
.xlsb	application/vnd.ms-excel.sheet.binary.macroEnabled.12
.xlam	application/vnd.ms-excel.addin.macroEnabled.12
.pptm	application/vnd.ms-powerpoint.presentation.macroEnabled.12
.ppsx	application/vnd.openxmlformats-officedocument.presentationml.slideshow
.ppsm	application/vnd.ms-powerpoint.slideshow.macroEnabled.12
.potx	application/vnd.openxmlformats-officedocument.presentationml.template
.potm	application/vnd.ms-powerpoint.template.macroEnabled.12
.one .onetoc2 .onetmp .onepkg	application/msonenote
*.3gpp	audio/3gpp, video/3gpp
*.ac3	audio/ac3
*.asf	allpication/vnd.ms-asf
*.au	audio/basic
*.dtd
*.dwg	image/vnd.dwg
*.dxf	image/vnd.dxf
*.jp2	image/jp2
*.jpe	image/jpeg
*.mp2	audio/mpeg, video/mpeg
*.mp3	audio/mpeg
*.mp4	audio/mp4, video/mp4
.mpeg，.mpg	video/mpeg
*.mpp	application/vnd.ms-project
*.ogg	application/ogg, audio/ogg
.pot，.pps，*.ppt	application/vnd.ms-powerpoint
*.rtf	application/rtf, text/rtf
*.svf	image/vnd.svf
*.tif	image/tiff
*.tiff	image/tiff
*.wdb	application/vnd.ms-works
*.wps	application/vnd.ms-works
*.xhtml	application/xhtml+xml
.xlc，.xlm，.xls，.xlt，*.xlw	application/vnd.ms-excel
*.xml	text/xml, application/xml