属性值有以下几个比较常用：

accept：表示可以选择的文件MIME类型，多个MIME类型用英文逗号分开，常用的MIME类型见下表。

multiple：是否可以选择多个文件，多个文件时其value值为第一个文件的虚拟路径。

<input id="fileId1" type="file" accept="image/png,image/gif" name="file" />

常用MIME类型

后缀名——MIME名称

*.3gpp——audio/3gpp,video/3gpp

*.ac3——audio/ac3

*.asf——allpication/vnd.ms-asf

*.au——audio/basic

*.css——text/css

*.csv——text/csv

*.doc——application/msword

*.dot——application/msword

*.dtd——application/xml-dtd

*.dwg——image/vnd.dwg

*.dxf——image/vnd.dxf

*.gif——image/gif

*.htm——text/html

*.html——text/html

*.jp2——image/jp2

*.jpe——image/jpeg

*.jpeg——image/jpeg

*.jpg——image/jpeg

*.js——text/javascript,——application/javascript

*.json——application/json

*.mp2——audio/mpeg,——video/mpeg

*.mp3——audio/mpeg

*.mp4——audio/mp4,——video/mp4

*.mpeg——video/mpeg

*.mpg——video/mpeg

*.mpp——application/vnd.ms-project

*.ogg——application/ogg,——audio/ogg

*.pdf——application/pdf

*.png——image/png

*.pot——application/vnd.ms-powerpoint

*.pps——application/vnd.ms-powerpoint

*.ppt——application/vnd.ms-powerpoint

*.rtf——application/rtf,——text/rtf

*.svf——image/vnd.svf

*.tif——image/tiff

*.tiff——image/tiff

*.txt——text/plain

*.wdb——application/vnd.ms-works

*.wps——application/vnd.ms-works

*.xhtml——application/xhtml+xml

*.xlc——application/vnd.ms-excel

*.xlm——application/vnd.ms-excel

*.xls——application/vnd.ms-excel

*.xlt——application/vnd.ms-excel

*.xlw——application/vnd.ms-excel

*.xml——text/xml,——application/xml

*.zip——aplication/zip

*.xlsx——application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

HTML5的 input:file上传类型控制